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1362108000: Genetic intellectual disability (disorder)


Status: current, Sufficiently defined by necessary conditions definition status (core metadata concept). Date: 01-Apr 2025. Module: SNOMED CT core

Descriptions:

Id Description Lang Type Status Case? Module
5444307014 Genetic intellectual disability en Synonym (core metadata concept) Active Entire term case insensitive (core metadata concept) SNOMED CT core
5444308016 Genetic intellectual disability (disorder) en Fully specified name Active Entire term case insensitive (core metadata concept) SNOMED CT core


534 descendants. Search Descendants:

Expanded Value Set


Outbound Relationships Type Target Active Characteristic Refinability Group Values
Genetic intellectual disability Is a Intellectual disability true Inferred relationship Some
Genetic intellectual disability Is a Genetic disease true Inferred relationship Some
Genetic intellectual disability Pathological process (attribute) Pathological developmental process true Inferred relationship Some 3
Genetic intellectual disability Interprets Intellectual ability true Inferred relationship Some 1
Genetic intellectual disability Has interpretation Impaired true Inferred relationship Some 1
Genetic intellectual disability Interprets Adaptation behavior (observable entity) true Inferred relationship Some 2
Genetic intellectual disability Has interpretation Impaired true Inferred relationship Some 2

Inbound Relationships Type Active Source Characteristic Refinability Group
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by the association of severe intellectual disability, strabismus, and anterior maxillary protrusion with vertical maxillary excess, open bite, and prominent crowded teeth. Mild cochlear hearing loss has been reported in addition. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by global developmental delay, intellectual disability, hypotonia, craniofacial dysmorphism (such as ridged metopic sutures, long palpebral fissures, broad nasal bridge, hypoplastic alae nasi, low-set, prominent ears, prominent midline tongue groove, and downturned mouth), congenital heart defects, and variable skeletal abnormalities including hip dysplasia, vertebral anomalies, and scoliosis. Additional reported manifestations include high pain tolerance and genitourinary anomalies. Brain imaging may show a thin corpus callosum or white matter abnormalities. Is a True Genetic intellectual disability Inferred relationship Some
A rare, X-linked, multiple congenital anomalies/dysmorphic malformation-intellectual disability syndrome characterized by developmental delay, mild to moderate intellectual disability, speech disturbance, behavioral problems (such as anxiety, hyperactivity, and aggressiveness) and mild facial dysmorphism (including facial hypotonia, thin arched eyebrows, ectropion, epicanthus, malar flatness, thick vermillion of the lips and prognathia). Additional variable manifestations include short stature, skeletal and genital anomalies, seizures, and autism spectrum disorders. Brain imaging may reveal cerebellar vermis hypoplasia, thin corpus callosum, and enlarged subarachnoid spaces. Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic, multiple congenital anomalies/dysmorphic features-intellectual disability syndrome characterized by developmental and speech delay, intellectual disability, feeding difficulties, failure to thrive, growth retardation, and associated malformations such as abnormality of fingers and toes (i.e. clinodactyly of the 5th finger, 2-3 toe syndactyly), microcephaly, heart defects, and upper airways anomalies. Observed facial dysmorphism includes hypertelorism, small, narrow or downslanting palpebral fissures, ptosis, epicanthus, ear malformations, broad nasal bridge, bulbous/prominent nose, short philtrum, thin lips, retrognathia/micrognathia, arched/cleft palate, and dental anomalies. Additional variable manifestations include hearing and visual impairment, seizures, joint anomalies, obesity, and behavioral/psychiatric disorders. Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic, intellectual disability malformation syndrome characterized by global developmental delay, intellectual disability, delayed speech and language development, epilepsy, autistic behavior, and moderate facial dysmorphism (including elongated face, narrow forehead, arched eyebrows, horizontal palpebral fissures, hypertelorism, epicanthus, midface flattening, short nose, long and featureless philtrum, thin upper lip, macrostomia, and prominent chin). Additional variable manifestations include microcephaly, hypotonia, hypertrichosis, and strabismus. Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic, syndromic intellectual disability characterized by intrauterine growth retardation, microcephaly, hypotonia, motor and neurodevelopmental delay, speech delay, intellectual disability, and mild dysmorphic features. Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic, syndromic intellectual disability characterized by psychomotor delay, hypotonia, feeding difficulties, failure to thrive, anomalies of the hands and feet (clinodactyly, camptodactyly, brachydactyly, feet malposition), and craniofacial dysmorphism. Associated prenatal growth retardation, and gastrointestinal, heart and eye anomalies have been reported. Is a True Genetic intellectual disability Inferred relationship Some
A multiple congenital anomalies/dysmorphic - intellectual disability syndrome characterized by feeding problems, growth retardation, microcephaly, developmental delay, digital and vertebral anomalies, joint laxity/dislocation, cardiac and renal defects, and dysmorphic facial features (including plagiocephaly, prominent forehead, bitemporal narrowing, bilateral coloboma, epicanthal folds, malformations of the outer and middle ear, wide nasal bridge, anteverted nares, prominent and bulbous nose tip, long philtrum, thin lips, high and narrow palate, micrognathia with prognathism/retrognathism, full cheeks, and short, broad neck). Additional variable manifestations include obstructive apneas, recurrent pneumonia, and seizures. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic, skeletal muscle disease with characteristics of early-onset hypotonia, muscle weakness, global developmental delay with intellectual disability and cardiomyopathy. Congenital structural heart defects and ichthyosiform cutaneous lesions have also been associated. Muscle biopsy shows characteristic enlarged mitochondria located at the periphery of muscle fibres. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic syndromic neurodevelopmental disorder with characteristics of moderate to mostly severe intellectual disability, speech impairment with normal or mildly delayed motor development and early-onset seizures often accompanied by developmental regression. Autistic behaviour and stereotypic movements are common. The disorder is caused by bi-allelic intragenic deletions (rarely duplications) or truncating variants in the CNTNAP2 gene (7q35-q36.1). It encodes contactin-associated protein 2 (CASPR2), a transmembrane protein from the neurexin superfamily, which is involved in neural-glia interactions and clustering of potassium channels in myelinated axons. Inheritance is autosomal recessive. Is a True Genetic intellectual disability Inferred relationship Some
A rare mitochondrial disease characterised by a variable phenotype comprising delayed psychomotor development or neurodevelopmental regression, hypotonia, seizures, microcephaly, optic atrophy, pyramidal signs, and peripheral neuropathy, among others. Age of onset and disease severity are also variable with some cases taking a fatal course in early infancy. Serum lactate levels may be elevated. Reported brain imaging findings include abnormal signals in the basal ganglia, cerebral and/or cerebellar atrophy, and white matter abnormalities. Is a True Genetic intellectual disability Inferred relationship Some
Cross syndrome Is a True Genetic intellectual disability Inferred relationship Some
A rare X-linked syndromic intellectual disability characterized by developmental delay and intellectual disability, early hypotonia, constipation, feeding problems, imperforate anus, characteristic behavior (affable, eager to please), and dysmorphic craniofacial features (such as relative macrocephaly, prominent forehead with frontal hair upsweep, hypertelorism, downslanting palpebral fissures, and open mouth). Additional manifestations are partial agenesis of the corpus callosum, sensorineural hearing loss, joint laxity, cardiac anomalies, and abnormalities of the fingers and toes, among others. Is a True Genetic intellectual disability Inferred relationship Some
X-linked intellectual disability-limb spasticity-retinal dystrophy-diabetes insipidus syndrome is a rare genetic neurometabolic disease characterized by severe intellectual disability, spastic quadriparesis, Leber congenital amaurosis and diabetes insipidus. Additional manifestations include facial dysmorphy (dolichocephalic skull, hypertelorism, deep-set eyes, hypoplastic nares, low-set ears), short stature, truncal hypotonia and axial hypertonia. Brain anomalies (e.g. thin corpus callosum with lack of isthmus and tapered splenium, hypoplasia or atrophy of the optic chiasm, prominent lateral ventricles, diminished white matter), described on magnetic resonance imaging, have been reported. High prenatal alpha-fetoprotein and intrauterine growth restriction is observed in routine pregnancy examination. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by variable degrees of developmental delay and intellectual disability with poor or absent speech, hypotonia, hypoplastic or absent corpus callosum, and facial dysmorphism (such as long face, frontal bossing, hypertelorism, downslanting palpebral fissures, and tented upper lip). Additional reported features include microcephaly, seizures, gait ataxia, scoliosis, and syndactyly of fingers, among others. Is a True Genetic intellectual disability Inferred relationship Some
A rare, syndromic intellectual disability characterized by hypotonia, global developmental delay, limited or absent speech, intellectual disability, macrocephaly, mild dysmorphic features, seizures and autism spectrum disorder. Associated ophthalmologic, heart, skeletal and central nervous system anomalies have been reported. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic disease characterized by microcephaly, global developmental delay, intellectual disability, abnormal muscle tone, and sensorineural hearing impairment. Additional variable manifestations include epilepsy, cortical visual impairment, gastrointestinal disturbances, growth restriction, scoliosis, as well as immunodeficiency and thrombocytopenia. Brain imaging may show cerebral atrophy, thin corpus callosum, and hypomyelination. Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic, syndromic intellectual disability characterized by mild to severe intellectual disability associated with variable features, including hypotonia, dyskinesia, spasticity, wide-based gait, microcephaly, epilepsy and behavioral problems. MRI imaging may show a corpus callosum hypoplasia or ventricular enlargement. Other variable features, such as joint hyperlaxity, skin pigmentary abnormalities, and visual impairment, have also been reported. Is a True Genetic intellectual disability Inferred relationship Some
X-linked intellectual disability-short stature-overweight syndrome is a multiple congenital anomalies syndrome characterised by borderline to severe intellectual disability, speech delay, short stature, elevated body mass index, a pattern of truncal obesity (reported in older males), and variable neurologic features (e.g. hypotonia, tremors, gait disturbances, behavioural problems, and seizure disorders). Less common manifestations include microcephaly, microorchidism and/or microphallus. Dysmorphic features have been reported in some patients but no consistent pattern has been noted. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic neurodevelopmental disorder characterized by global developmental delay (DD) and variable degrees of intellectual disability (ID) with delayed or limited/absent speech development associated with neonatal hypotonia, feeding difficulties, cardiac anomalies and dysmorphic facial features, predominantly broad nasal tip and thin, tented upper lip. Microcephaly, frequent infections, gastrointestinal and/or ocular anomalies have also been described. Is a True Genetic intellectual disability Inferred relationship Some
Syndrome with the association of stubby, coarse, sparse and fragile hair, eyebrows and eyelashes with photosensitivity and nonprogressive intellectual deficit, without a demonstrable metabolic aberration. It has been described in three sisters born to consanguineous parents. Is a True Genetic intellectual disability Inferred relationship Some
Baraitser-Winter syndrome (BWS) is a malformation syndrome, characterized by facial dysmorphism (hypertelorism with ptosis, broad bulbous nose, ridged metopic suture, arched eyebrows, progressive coarsening of the face), ocular coloboma, pachygyria and/or band heterotopias with antero-posterior gradient, progressive joint stiffening, and intellectual deficit of variable severity, often with severe epilepsy. Pachygyria - epilepsy - intellectual disability - dysmorphism (Fryns-Aftimos syndrome) corresponds to the appearance of BWS in elderly patients. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by developmental delay, moderate to severe intellectual disability, dysmorphic features including craniosynostosis, micro-/retrognathia, cleft palate, and brachydactyly, and short stature. Seizures, skeletal anomalies (such as arthrogryposis, gracile bones, and pathological fractures), and renal abnormalities have also been described. Cerebral MRI may show periventricular white matter changes and ventriculomegaly. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by developmental delay with intellectual disability, postnatal growth deficiency causing profound limb shortening with proximal and distal segments involvement, narrow chest, abnormalities of the spine, pelvis, and metaphyses, corneal clouding, and patent ductus arteriosus. Dysmorphic facial features include hypertelorism, prominent eyes, depressed nasal bridge, and short upturned nose. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic syndrome with a central nervous system malformation as a major feature, characterized by cortical malformations including posterior predominant lissencephaly and diffuse pachygyria, as well as midline crossing defects, thin corpus callosum, dysplastic hippocampi, narrowing of the brainstem with small pons and midbrain, widening of the medulla, and small cerebellum. Clinically, patients present global developmental delay, severe intellectual disability with poor or absent speech, axial hypotonia, and early-onset seizures, among others. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic disorder of magnesium transport characterized by infantile onset of generalized seizures and severe hypomagnesemia due to massive renal magnesium wasting. Seizures persist despite magnesium supplementation and are associated with significant global developmental delay and intellectual disability. Brain MRI may show reduced cerebral volume. Is a True Genetic intellectual disability Inferred relationship Some
A rare mitochondrial oxidative phosphorylation disorder characterized by early onset of severe developmental delay (sometimes with regression of developmental milestones) and intellectual disability, poor or absent speech, and hypotonia. Other features include movement disorder, seizures, or microcephaly, among others. Brain imaging may show features of Leigh syndrome with signal abnormalities in the basal ganglia or mid brain, cerebellar atrophy, or thin corpus callosum. Is a True Genetic intellectual disability Inferred relationship Some
A rare primary bone dysplasia characterized by microcephaly, developmental delay and intellectual disability, sensorineural hearing loss, retinal degeneration, and skeletal dysplasia. Musculoskeletal abnormalities include delayed ossification of epiphyses, spondyloepimetaphyseal dysplasia, short stature, severe spinal deformities, and severe joint laxity resulting in multiple joint dislocations. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic syndrome with characteristics of developmental delay and mild to moderate intellectual disability. Verbal language acquisition is usually delayed, with restricted language. The congenital heart defects are present in 41% of individuals, the most frequent being interatrial communication and interventricular communication. The syndrome is caused by heterozygous, usually de novo pathogenic or likely pathogenic variants in the CDK13 gene (7p14.1), coding for a protein which regulates transcription. Transmission is autosomal dominant however, in most situations, the pathogenic variants arise de novo, and thus, the risk of sibling recurrence is low. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic multiple congenital anomalies/dysmorphic syndrome with characteristics of microcephaly, severe global developmental delay and intellectual disability, hypotonia, respiratory insufficiency, failure to thrive, and congenital anomalies affecting the skeleton, eyes, and several organ systems. Seizures and hearing loss are sometimes observed. Independent ambulation and meaningful speech are not attained. Common dysmorphic facial features include small forehead, biparietal narrowing, flat face, hypertelorism, arched eyebrows, short, upslanting palpebral fissures, wide nasal bridge, small, upturned nose, forward facing ears, and micrognathia. Brain imaging shows structural abnormalities in all patients. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic neurodevelopmental disorder characterised by global developmental delay, severe intellectual disability and absence of expressive language. Muscular hypotonia, seizures, autistic behaviour and stereotypic movements are common. The disorder is caused by homozygous or compound heterozygous intragenic deletions or truncating variants in the NRXN1 gene (2p16.3). NRXN1 belongs to the evolutionarily conserved family of neurexins, presynaptic transmembrane proteins and has an important role in synaptic function. Inheritance is autosomal recessive. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by intellectual disability, obesity, macrocephaly, behavioral abnormalities (such as aggressive tantrums and autistic-like behavior), and delayed speech development. Dysmorphic facial features include large, square forehead, prominent supraorbital ridges, broad nasal tip, large ears, prominent lower lip, and minor dental anomalies such as small upper lateral incisors and central incisor gap. Is a True Genetic intellectual disability Inferred relationship Some
A form of pontocerebellar hypoplasia characterized by microcephaly, severe global developmental delay and intellectual disability, dysmorphic facial features, cerebellar syndrome, and pontocerebellar hypoplasia on brain imaging. Behavioral abnormalities are frequently observed. Other reported manifestations include seizures, ocular anomalies, recurrent respiratory infections, and thin or absent corpus callosum, among others. Is a True Genetic intellectual disability Inferred relationship Some
A form of pontocerebellar hypoplasia characterised by severe, progressive microcephaly and severe global developmental delay apparent from birth, severe intellectual disability with lack of social interactions and absence of speech, and pontocerebellar hypoplasia and complete or partial agenesis of the corpus callosum on brain imaging. In addition, affected individuals often present hypotonia, spastic tetraplegia, and early-onset seizures. Chronic anaemia and thrombocytopenia have also been reported. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic syndromic intellectual disability disorder characterized by global developmental delay, often with severe hypotonia and limited mobility, intellectual disability (mild to severe) with absent or significantly impaired speech and behavioral problems. Craniofacial features include blepharophimosis, epicanthal folds, sparse eyebrows and eyelashes, broad nasal bridge, short nose with downturned tip, open mouth with thin upper vermillion, and abnormal ears. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome characterized by mild to severe intellectual disability frequently co-occurring with behavioral problems (including anxiety, attention deficit hyperactivity disorder and autistic spectrum disorder), variable somatic overgrowth, macrocephaly and distinctive dysmorphic facial features including high hairline, frontal bossing, downslanting palpebral fissures, telecanthus, hypertelorism, deep-set eyes and full cheeks. Pierre Robin sequence with submucous cleft has also been reported. Additional clinical features include skeletal abnormalities, hypotonia, cardiac anomalies, hypothyroidism, cryptorchidism, visual disturbances and ectodermal problems such as sparse hair, thin nails, and abnormal dentition. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome characterized by developmental delay, severe intellectual disability, severe speech and communication problems and distinctive dysmorphic faces (high hairline, thin eyebrows, hypertelorism, dysmorphic ears, broad nasal bridge and tip, and narrow jaw). Height is not affected. Some patients may also present autistic behaviors. Is a True Genetic intellectual disability Inferred relationship Some
A rare constitutional aplastic anaemia characterised by aplastic anaemia, intellectual disability, short stature, and microcephaly. Skin pigmentation or cafe au lait spots are often present. Majority of the patients present global developmental delay with impaired motor skills, learning disabilities, speech delay whereas some patients also may have behavioural problems including autistic features. Patients often develop premalignant myelodysplastic syndromes or leukaemia. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome characterized by central nervous system abnormalities (particularly cerebellar hypoplasia), congenital microcephaly, intellectual disability, severe neurodevelopmental delay, growth impairment, dystonia, eye abnormalities (particularly cataract whereas retinal dystrophy and Leber congenital amaurosis are also reported) and congenital dyserythropoietic anemia. Additional clinical features may include other structural brain abnormalities (such as cerebral atrophy, basal ganglia atrophy, brainstem hypoplasia), feeding difficulties, sleep disturbances, hepatomegaly, and sensorineural deafness. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome with characteristics of developmental delay, speech delay and variable degree of intellectual disability (mostly mid-to-moderate but some patients may also have normal intelligence) due to CHD4 gene mutations. Even though clinical manifestations are significantly variable among patients, most patients manifest dysmorphic facial features (could sometimes include macrocephaly), congenital heart defects, hypotonia and ophthalmologic abnormalities. Other clinical features may include brain structure anomalies, skeletal anomalies, hearing impairment and gonadal abnormalities. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic multiple congenital anomalies/dysmorphic syndrome with characteristics of congenital heart defect (including atrial or ventricular septal defects and aortic coarctation), cleft palate, and variable degree of developmental delay and intellectual disability. Most patients reported to also have autism spectrum disorder. Overlapping facial features were reported in some patients including broad forehead with high anterior hairline, finely arched eyebrows, short philtrum, thin or tented upper lip. Other clinical features may involve mild distal skeletal abnormalities, hypotonia, hearing loss, feeding problems and skin abnormalities. Is a True Genetic intellectual disability Inferred relationship Some
A rare neurodevelopmental syndrome characterised by developmental delay, intellectual disability of varying severity and weight disorders (overweight/obesity and eating behaviour disorders including hyperphagia, tachyphagia, food impulsiveness and a feeling of permanent hunger). Additional clinical features include learning difficulties (may be combined with dysphasia, dyspraxia, dyscalculia, dysgraphia), severe language delay, behavioural disorders (stereotypies, impulsiveness or intolerance to frustration, self or hetero aggression, autism spectrum disorder) and non-specific dysmorphism. Epilepsy and ophthalmologic abnormalities can also be observed. Endocrine abnormalities are rarely associated. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic neurological syndrome of variable severity with characteristics of progressive spasticity affecting predominantly the lower limbs. Most patients manifest global developmental delay, moderate to severe intellectual disability and white matter abnormalities in infancy complicated by variable features including seizures, episodic respiratory failure, joint contractures and ocular problems. Some patients have normal early development until later childhood followed by regression in motor, cognitive and language skills over time. Some patients manifest only spastic paraplegia. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic neurological syndrome with characteristics of cerebellar ataxia, neurodevelopmental delay, poor motor development and growth, mild to severe intellectual disability and infantile-onset hypotonia. Many patients have cardiac conduction and rhythm anomalies (including bundle branch block, bradycardia, sinus node dysfunction, intraventricular conduction delay, atrioventricular block, and ventricular tachycardia) in childhood or adolescence. Additional clinical features may include variable ocular anomalies and dysmorphic features. Is a True Genetic intellectual disability Inferred relationship Some
A rare developmental defect during embryogenesis with characteristics of the presence of major features of both blepharophimosis-intellectual disability syndrome and genitopatellar syndrome. These major features may include blepharophimosis, ptosis, hypomimia, skeletal features like patellar a/hypoplasia and renal and/or genital malformations. Is a True Genetic intellectual disability Inferred relationship Some
A rare Prader-Willi-like syndrome with characteristics of intellectual disability, morbid obesity, hypogonadotrophic hypogonadism, hyperphagia and developmental delay. Endocrine disorders including hypothyroidism and insulin resistance can be observed. Unlike Prader-Willi syndrome, profound muscular hypotonia, feeding difficulties in neonates, short stature and growth hormone deficiency are not observed. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome characterised by developmental delay, intellectual disability (ranging from mild to severe), speech delay or speech disorder and cupped and/or low-set ears. Patients may also have brain abnormalities, hypotonia, drooling and vision problems. Seizures and sleep disturbance were reported for some patients. Is a True Genetic intellectual disability Inferred relationship Some
A rare renal tubular disease characterised by hypomagnesaemia due to renal magnesium wasting, recurrent generalised seizures, mild to moderate intellectual disability, speech delay and obesity due to CNNM2 mutations. Most patients also manifest motor skill defects and hyperkinesia. Majority of the affected individuals do not exhibit brain anomalies. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome characterized by severe intellectual disability, global developmental delay with no speech (some patients may have limited speech), inability or difficulty to walk, microcephaly, and early-onset cataract. Additional clinical features may include hypotonia, spasticity, endocrine/metabolic diseases and immunodeficiency with lymphopenia. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome characterized by mild or moderate intellectual disability, developmental delay, short stature and facial dysmorphism (long ears, prominent nasal tip, low columella, thin upper lip, broad mouth and prominent chin) due to KDM3B mutations. Neonatal feeding difficulties, childhood hypotonia, and behavior problems were also reported in some patients. Is a True Genetic intellectual disability Inferred relationship Some
A rare disorder of magnesium transport characterised by hypomagnesaemia due to renal wasting, leading to tetany, early-onset seizures, impaired psychomotor development, and moderate intellectual disability. Secondary hypocalcaemia and obesity are absent. Is a True Genetic intellectual disability Inferred relationship Some
A rare primary bone dysplasia characterised by severe spondyloepiphyseal dysplasia, sensorineural hearing loss, intellectual disability and Leber congenital amaurosis. Brain anomalies (including delayed myelinisation, white matter hyperintensity, hypomyelinating leucoencephalopathy, cerebral and cerebellar hypoplasia/atrophy), hypotonia, ataxia, dysmorphic facial features (including deep nasal bridge and large mouth) and irregular dentition were also reported. Is a True Genetic intellectual disability Inferred relationship Some
2p21 microdeletion syndrome without cystinuria is a rare partial autosomal monosomy characterized by weak fetal movements, severe infantile hypotonia and feeding difficulties that spontaneously improve with time, urogenital abnormalities (hypospadias or hypoplastic labia majora), global development delay, mild intellectual disability and facial dysmorphism (dolichocephaly, frontal bossing, bilateral ptosis, midface retrusion, open mouth with tented upper lip vermilion). Affected individuals have borderline elevated serum lactate but no cystinuria. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome characterized by global developmental delay, moderate to severe intellectual disability, language delay and asymptomatic persistence of fetal hemoglobin. Joint laxity and microcephaly are commonly observed. Majority of the patients present with variable dysmorphic features (including strabismus, downslanting palpebral fissures, anteverted nose with small nares and full tip, external ear anomalies, thin upper lip and everted lower lip). Behavior problems including anxiety, recurrent hand flapping/biting and attention deficit can also be observed. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic intellectual disability syndrome characterized by global developmental delay, intellectual disability, severe speech delay, behavioral abnormalities (including impulsivity, compulsivity, stubbornness, manipulative behaviors, temper tantrums, and aggressive behaviors), autism spectrum disorder and mild and variable dysmorphic facies (including deep-set eyes and a prominent nasal septum, extending below the alae nasi) due to point mutation of USP7 gene or 16p13.2 microdeletion where USP7 is completely or partially deleted. Behavioral abnormalities are more pronounced in microdeletion. Patients may also have hypotonia, feeding problems, delayed walking with unsteady gait, hypogonadism in males, seizures and ocular anomalies (such as myopia, esotropia, strabismus, and nystagmus). Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic, syndromic intellectual disability disorder characterized by craniofacial features, global developmental delay, intellectual disability and variable neurobehavioral abnormalities (autism spectrum disorder, aggressiveness, and self-injury). Additional features include vision abnormalities and variable sensorineural hearing loss, as well as short stature, hypotonia and gastrointestinal manifestations (e.g. poor feeding, gastroesophageal reflux, constipation). Is a True Genetic intellectual disability Inferred relationship Some
A developmental disorder characterized by typical craniofacial features, prenatal and postnatal growth impairment, intellectual disability, severe delayed psychomotor development, seizures, and hypotonia. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies syndrome characterized by tall stature due to postnatal overgrowth, mild to moderate intellectual disability, joint hypermobility and subtle distinctive facial features, which often become apparent during adolescence (such as round face, low-set, thick horizontal eyebrows, narrow palpebral fissures and prominent upper-central incisors). Overweight, hypotonia, behavioral and psychiatric problems are common. Other clinical features may involve seizures, cryptorchidism and cardiovascular diseases (including congenital heart disease and aortic root dilatation). Is a True Genetic intellectual disability Inferred relationship Some
C syndrome is a rare multiple congenital anomaly/intellectual disability syndrome characterized by trigonocephaly and metopic suture synostosis, dysmorphic facial features, short neck, skeletal anomalies, and variable intellectual disability. Is a True Genetic intellectual disability Inferred relationship Some
Disease with characteristics of recurrent seizures, encephalopathy and intellectual disability with onset of symptoms typically beginning in infancy. Seizures may be refractory and intellectual disability may be mild to severe. Sudden unexpected death in epilepsy may occur in rare cases. The disease is caused by mutations in the SCN8A gene, which provides instructions for making the alpha subunit of Nav1.6. Follows an autosomal dominant pattern of inheritance however most cases of this condition result from de novo mutation. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic developmental and neurological disorder characterised by the association of partial bilateral aniridia (or iris hypoplasia), with non-progressive cerebellar ataxia, intellectual disability, and congenital hypotonia. Is a True Genetic intellectual disability Inferred relationship Some
McDonough syndrome is a rare, multiple congenital anomalies/dysmorphic syndrome characterized by facial dysmorphism (prominent superciliary arcs, synophrys, strabismus, large, anteverted ears, large nose, malocclusion of teeth), delayed psychomotor development, intellectual disability and congenital heart defects (e.g. pulmonic stenosis, patent ductus arteriosus, atrial septal defect). Additional features include thorax deformation (pectus excavatum/carinatum), kyphoscoliosis, diastasis recti and cryptorchidism. There have been no further descriptions in the literature since 1984. Is a True Genetic intellectual disability Inferred relationship Some
Biemond syndrome type 2 (BS2) is a rare genetic neurological and developmental disorder reported in a very small number of patients with a poorly defined phenotype which includes iris coloboma, short stature, obesity, hypogonadism, postaxial polydactyly, and intellectual disability. Hydrocephalus and facial dysostosis were also reported. BS2 shares features with Bardet-Biedl syndrome. There have been no further descriptions in the literature since 1997. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome characterized by the association of intellectual deficit, facial dysmorphism (a highly arched palate, pointed chin, and small mouth, hypotelorism, a long nose and large protruding ears), arachnodactyly, hypogenitalism (undescended testes and hypospadias) and failure to thrive. Is a True Genetic intellectual disability Inferred relationship Some
Kagami-Ogata syndrome is a rare genetic disease characterized by polyhydramnios (mostly due to placentomegaly), fetal macrosomia, abdominal wall defects, skeletal abnormalities (including bell-shaped thorax, coat-hanger appearance of the ribs and decreased mid to wide thorax diameter ratio in infancy), feeding difficulties and impaired swallowing, dysmorphic features (hairy forehead, full cheeks, protruding philtrum, micrognathia), developmental delay and intellectual disability. Additional features may include kyphoscoliosis, joint contractures, diastasis recti, muscular hypotonia. There is increased risk of hepatoblastoma. Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic, neurodevelopmental disorder characterized by global developmental delay, borderline to severe intellectual disability, feeding difficulties, behavioral anomalies, vision anomalies and mild facial dysmorphism. Other associated features may include microcephaly, short stature, urogenital or palatal anomalies (e.g. cleft palate), minor cardiac defects, recurrent infections or hearing loss. Is a True Genetic intellectual disability Inferred relationship Some
A partial deletion of the long arm of chromosome 4 characterized by complex behavioral difficulties, developmental and delay/ intellectual disability, and minor dysmorphic features, including subtle facial asymmetry (most prominent in the mandible), mild hypotelorism, long nasal bridge, small low-set ears, narrow mouth, and mild hand deformities, such as bilateral short 5th metacarpals, and short hands. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome with intellectual disability characterized by severe congenital contractures of the limbs and face, hypotonia, neonatal respiratory distress, and global developmental delay. Dysmorphic facial features include downslanting palpebral fissures, broad nasal bridge, large nares, long philtrum, and deep nasolabial folds, among others. Limb deformities (camptodactyly, clubfoot), short neck, scoliosis, as well as seizures have also been reported. Brain MRI may show cerebral and cerebellar atrophy in some cases. Is a True Genetic intellectual disability Inferred relationship Some
PDE4D haploinsufficiency syndrome is a rare syndromic intellectual disability characterized by developmental delay, intellectual disability, low body mass index, long arms, fingers and toes, prominent nose and small chin. Is a True Genetic intellectual disability Inferred relationship Some
A rare syndromic intellectual disability characterized by global developmental delay, gastrointestinal problems, hypotonia, delayed speech, behavioral and sleep problems, pain insensitivity, seizures, structural brain anomalies, dysmorphic features, visual problems, early tooth eruption and autistic features. Is a True Genetic intellectual disability Inferred relationship Some
Blepharophimosis, intellectual disability syndrome (disorder) Is a True Genetic intellectual disability Inferred relationship Some
A multiple congenital developmental anomalies syndrome characterized by arachnodactyly of fingers and toes associated with craniofacial dysmorphism (including abnormal cranial ossification, frontal bossing, flat calvaria, shallow deformed orbits resulting in exophthalmos, midface hypoplasia and micrognathia), feeding difficulties in infancy, infantile muscular hypotonia, and developmental delay leading to intellectual disability. Is a True Genetic intellectual disability Inferred relationship Some
A rare multiple congenital anomalies/dysmorphic syndrome characterized by facial dysmorphism (brachycephaly, long, narrow, triangular face, prominent forehead, hypertelorism, flat philtrum, microstomia, thin lips, hypoplastic maxilla), marfanoid habitus with arachnodactyly, and moderate to severe intellectual disability. Additional features may include clinodactyly, triphalangeal thumbs, hammer-shaped toes, hyperextensible joints, hypotonia, hyperreflexia and underdeveloped musculature. Delayed external genitalia development, as well as seizures and mitral regurgitation have been reported in some cases. There have been no further descriptions in the literature since 1995. Is a True Genetic intellectual disability Inferred relationship Some
Caudal appendage-deafness syndrome is characterized by caudal appendage, short terminal phalanges, deafness, cryptorchidism, intellectual deficit, short stature and dysmorphism. It has been described in monozygotic twin boys. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic neurological disorder characterized by early-onset progressive leukoencephalopathy, severe developmental delay, early-onset or congenital deafness (only few cases reported without hearing loss), and visual impairment. All patients manifest calcifications in brain and spinal cord. Cognitive impairment, seizures, hypotonia, spastic tetraplegia or quadriplegia are observed in the majority of the patients. Variable features may include microcephaly and anemia. Is a True Genetic intellectual disability Inferred relationship Some
Coffin-Siris syndrome Is a True Genetic intellectual disability Inferred relationship Some
Craniofaciofrontodigital syndrome is a rare multiple congenital anomalies syndrome characterized by mild intellectual disability, short stature, cardiac anomalies, mild dysmorphic features (macrocephaly, prominent forehead, hypertelorism, exophthalmos), cutis laxa, joint hyperlaxity, wrinkled palms and soles and skeletal anomalies (sella turcica, wide ribs and small vertebral bodies). Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by global developmental delay, intellectual disability, short stature, skeletal abnormalities (such as brachydactyly and vertebral anomalies), obesity, cardiac, respiratory, and genitourinary anomalies, and dysmorphic facial features (including coarse facies, thick eyebrows, synophrys, hypertelorism, short, upturned nose, and long philtrum). Additional reported manifestations are microcephaly, hearing impairment, cataract, and gastroesophageal reflux. Is a True Genetic intellectual disability Inferred relationship Some
Cryptorchidism-arachnodactyly-intellectual disability syndrome is a rare, multiple congenital anomalies syndrome characterized by psychomotor delay, severe intellectual deficit, severe muscle hypoplasia (with absence of subcutaneous fatty tissue), generalized contractures, craniofacial dysmorphic features (dolichocephaly, esotropia, ears of unequal size, high palate), chest and spinal deformities (i.e. sternum shifted to side, kyphoscoliosis), pulmonary anomalies (unilateral hypoplastic bronchial system), arachnodactyly, and genital abnormalities (cryptorchidism, hypospadias, testicular agenesis). Repeated respiratory tract infections and atelectasis are also associated. There have been no further descriptions in the literature since 1970. Is a True Genetic intellectual disability Inferred relationship Some
A rare genetic neurodevelopmental disorder characterized by early-onset drug-resistant seizures and severe neurodevelopmental impairment with major motor development delay. Is a True Genetic intellectual disability Inferred relationship Some
A rare syndrome with 46,XY disorder of sex development characterised by variable degrees of intellectual disability, short stature, severe genital anomalies resulting in sexual ambiguity (such as pseudovaginal perineoscrotal hypospadias and persistence of Müllerian structures), and ocular anomalies (microphthalmia, coloboma). Craniofacial peculiarities (coarse features, deep set eyes), spina bifida, imperforate anus, and sensorineural hearing loss were also described. No new cases have been reported since 1994. Is a True Genetic intellectual disability Inferred relationship Some
Deafness-genital anomalies-metacarpal and metatarsal synostosis syndrome is characterized by sensorineural deafness, bilateral synostosis of the 4th and 5th metacarpals and metatarsals, genital anomalies (hypospadias in males), psychomotor delay and abnormal dermatoglyphics. So far, it has been described in two unrelated patients. Facial dysmorphism was noted in both patients (prominent forehead, ear anomalies, facial asymmetry and an open mouth appearance). Is a True Genetic intellectual disability Inferred relationship Some
Hepatic fibrosis-renal cysts-intellectual disability syndrome is a rare, syndromic intellectual disability characterized by early developmental delay with failure to thrive, intellectual disability, congenital hepatic fibrosis, renal cystic dysplasia, and dysmorphic facial features (bilateral ptosis, anteverted nostrils, high arched palate, and micrognathia). Variable additional features have been reported, including cerebellar anomalies, postaxial polydactyly, syndactyly, genital anomalies, tachypnea. There have been no further descriptions in the literature since 1987. Is a True Genetic intellectual disability Inferred relationship Some
Dysmorphism-cleft palate-loose skin syndrome is a rare, genetic developmental defect during embryogenesis characterized by severe psychomotor delay, intellectual disability, congenital, symmetrical circumferential skin creases of arms and legs, cleft palate, and facial dysmorphism (including elongated face, high forehead, blepharophimosis, short palpebral fissures, microphthalmia, microcornea, epicanthic folds, telecanthus, microtia, posteriorly angulated ears, broad nasal bridge, microstomia and micrognathia). Additional features reported include short stature, microcephaly, hypotonia, pectus excavatum, severe scoliosis, hypoplastic scrotum, and mixed hearing loss. Is a True Genetic intellectual disability Inferred relationship Some
Epiphyseal dysplasia-hearing loss-dysmorphism syndrome is a rare multiple congenital anomalies/dysmorphic syndrome characterized by developmental delay, intellectual disability, short stature, sensorineural hearing impairment, facial dysmorphism (including epicanthus, broad, depressed nasal bridge, broad, fleshy nasal tip, mildly anteverted nares, deep nasolabial folds, broad mouth with thin upper lip) and skeletal anomalies (including abnormally placed thumbs, brachydactyly, scoliosis, dysplastic carpal bones). Patients also present severe behavior disturbances (aggression, hyperactivity), as well as hypopigmented skin lesions and hypoplastic digital patterns. There have been no further descriptions in the literature since 1992. Is a True Genetic intellectual disability Inferred relationship Some
Intellectual disability, Wolff type is a rare intellectual disability syndrome characterized by severe intellectual disability, characteristic facial features (low anterior hairline, upward slanting palpebral fissures, ocular hypertelorism, broad, bulbous nose, large ears with helix incompletely developed, thick lips, and micrognathia) and additional anomalies including peripheral joint contractures, delayed skeletal maturation, bilateral cleft lip and palate, strabismus, terminal hypoplasia of fingers, hypospadias, and bilateral inguinal hernias. Is a True Genetic intellectual disability Inferred relationship Some
Intellectual disability, Birk-Barel type is a rare, genetic, syndromic intellectual disability characterized by congenital central hypotonia, developmental delay, moderate to severe intellectual disability and subtle dysmorphic features which evolve over time (dolichocephaly, myopathic facies, ptosis, short and broad philtrum, tented upper lip vermillion, palatal anomalies, mild micro- and/or retrognathia). Patients present reduced facial movements, lethargy, weak cry, transient neonatal hypoglycemia, severe feeding difficulties and failure to thrive. Dysphagia, particularly of solid food, asthenic body build, joint contractures and scoliosis are additional features. Is a True Genetic intellectual disability Inferred relationship Some
A neurological disorder with characteristics of moderate to severe developmental delay and intellectual disability and mild dysmorphic features. Early symptoms include hypotonia, delayed development of motor skills, speech delay, hypertelorism, broad nasal bridge, and fingers with tapered ends. Other features include microcephaly, seizures, recurrent ear infections, strabismus, amblyopia and hyperopia. Behavioral problems such as hyperactivity, attention deficit disorder, aggression, anxiety and autism spectrum occur in some cases. Caused by mutations in the HIVEP2 gene leading to a shortage of functional HIVEP2 protein. Inherited in an autosomal dominant pattern however most cases of this condition result from de novo mutations in the gene. Is a True Genetic intellectual disability Inferred relationship Some
This syndrome is characterized by the association of hypogonadism due to primary gonadal failure, mitral valve prolapse, mild intellectual deficit and short stature. Is a True Genetic intellectual disability Inferred relationship Some
Intellectual disability-seizures-macrocephaly-obesity syndrome is a rare syndromic obesity due to complex chromosomal rearrangement characterized by development delay and intellectual disability, childhood-onset obesity, seizures, poor coordination and broad-based gait, macrocephaly and mild dysmorphic features (such as narrow palpebral fissures, malar hypoplasia and thin upper lips), eczema, ocular abnormalities and a social personality. Is a True Genetic intellectual disability Inferred relationship Some
Intellectual disability-polydactyly-uncombable hair syndrome is a multiple congenital anomalies/dysmorphic syndrome characterized by intellectual disability, postaxial polydactyly, phalangeal hypoplasia, 2-3 toe syndactyly, uncombable hair and facial dysmorphism (including frontal bossing, hypotelorism, narrow palpebral fissures, nasal bridge and lips, prominent nasal root, large abnormal ears with prominent antihelix, poorly folded helix, underdeveloped lobule and antitragus, and micrognathia evolving into prognathism). Cryptorchidism, conductive hearing loss and progressive thoracic kyphosis were also reported. Is a True Genetic intellectual disability Inferred relationship Some
Intellectual disability-brachydactyly-Pierre Robin syndrome is a rare developmental defect during embryogenesis syndrome characterized by mild to moderate intellectual disability and psychomotor delay, Robin sequence (including severe micrognathia and soft palate cleft) and distinct dysmorphic facial features (e.g. synophrys, short palpebral fissures, hypertelorism, small, low-set, and posteriorly angulated ears, bulbous nose, long/flat philtrum, and bow-shaped upper lip). Skeletal anomalies, such as brachydactyly, clinodactyly, small hands and feet, and oral manifestations (e.g. bifid, short tongue, oligodontia) are also associated. Additional features reported include microcephaly, capillary hemangiomas on face and scalp, ventricular septal defect, corneal clouding, nystagmus and profound sensorineural deafness. Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic, syndromic intellectual disability disorder characterized by mild to moderate intellectual disability, facial dysmorphism (including a long face, deep-set eyes, narrow-based, broad nose with nostril colobomata, mandibular prognathism), hypergonadotrophic hypogonadism, eunuchoid habitus, diabetes mellitus type 1, and epilepsy. There have been no further descriptions in the literature since 1990. Is a True Genetic intellectual disability Inferred relationship Some
Intellectual disability-short stature-hypertelorism syndrome is a rare genetic syndromic intellectual disability characterized by short stature, mild to moderate intellectual disability, craniofacial dysmorphism (prominent broad 'square' forehead, hypertelorism, depressed nasal bridge, broad nasal tip and anteverted nares) and early hypotonia, typically present until infancy. There have been no further descriptions in the literature since 1991. Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic, syndromic intellectual disability disorder, with highly variable phenotype, typically characterized by mild to severe global development delay, severe speech and language impairment, mild to severe intellectual disability, dysphagia, hypotonia, relative to true macrocephaly, and behavioral problems that may include autistic features, hyperactivity, and mood lability. Facial gestalt typically features a broad, prominent forehead, hypertelorism, downslanting palpebral fissures, ptosis, a short bulbous nose with broad tip, thick vermilion border, wide, and open mouth with downturned corners. Brain, cardiac, urogenital and ocular malformations may be associated. Is a True Genetic intellectual disability Inferred relationship Some
A rare, syndromic intellectual disability characterized by macrocephaly, short stature, intellectual disability, variable degree of spastic paraplegia, central nervous system malformations (hydrocephalus, Dandy-Walker malformation), and dysmorphic features, such as high and broad forehead, midface hypoplasia, and small and broad hands and feet. There have been no further descriptions in the literature since 1993. Is a True Genetic intellectual disability Inferred relationship Some
A rare, genetic multiple congenital anomalies/dysmorphic syndrome characterized by severe short stature and craniofacial dysmorphism (microcephaly, narrow face with flat cheeks, ptosis, prominent nose with a convex ridge, low-set ears with small or absent lobes, high-arched/cleft palate, micrognathia), associated with premature graying and loss of scalp hair, redundant, dry and wrinkled skin of the palms, premature senility and varying degrees of intellectual disability. Cryptorchidism and skeletal anomalies may also be observed. There have been no further descriptions in the literature since 1970. Is a True Genetic intellectual disability Inferred relationship Some
A rare, multiple congenital anomalies/dysmorphic syndrome characterized by microcephaly, intellectual disability, seizures, and congenital heart defects (e.g. atrial/ventricular septal defect, hypoplastic aortic arch with persistent ductus arteriosus). Additional manifestations include mild hypothyroidism, skeletal abnormalities, micropenis, delayed psychomotor development, dysmorphic facial features (including epicanthus, depressed nasal bridge, prominent antitragus), and pulmonary vascular occlusive disease. There have been no further descriptions in the literature since 1989. Is a True Genetic intellectual disability Inferred relationship Some
Polyneuropathy-intellectual disability-acromicria-premature menopause syndrome is a rare genetic syndromic intellectual disability characterized by intellectual disability, polyneuropathy, short stature and short limbs, brachydactyly, and premature ovarian insufficiency. Only one familial case with three affected females was described and there have been no further descriptions in the literature since 1971. Is a True Genetic intellectual disability Inferred relationship Some
Nijmegen breakage syndrome-like disorder is a rare, genetic multiple congenital anomalies/dysmorphic syndrome characterized by growth retardation, short stature, developmental delay, intellectual disability, craniofacial dysmorphism (i.e. severe microcephaly, sloping forehead, prominent eyes, broad nasal ridge, hypoplastic nasal septum, epicanthal folds), spontaneous chromosomal instability, cellular hypersensitivity to ionizing radiation and radioresistant DNA synthesis, without severe infections, immunodeficiency or cancer predisposition. Additional reported features include mild spasticity, slight and nonprogressive ataxia, hyperopia, multiple pigmented nevi, widely spaced nipples, and clinodactyly. Is a True Genetic intellectual disability Inferred relationship Some
A rare primary bone dysplasia characterized by global developmental delay, hypotonia, ossification anomalies of the cranial vault, abnormalities of the long bones due to defective remodeling, thoracic deformity, and progressive osteopenia. Dysmorphic craniofacial features include microcephaly, hypertelorism, narrow mouth, cleft palate, and micrognathia. Is a True Genetic intellectual disability Inferred relationship Some

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