Dominant mutations in ATP1A1, encoding the alpha-1 isoform of the Na<sup>+</sup> /K<sup>+</sup> -ATPase, have been recently reported to cause an axonal to intermediate type of Charcot-Marie-Tooth disease (ie, CMT2DD) and a syndrome with hypomagnesemia, intractable seizures and severe intellectual disability.
Mutations in SZT2 have been reported in very few patients and features range from mild to moderate intellectual disability without seizures to severe intellectual disability with epileptic encephalopathies with severe developmental delay.
Using exome sequencing, we have identified de novo variants in MAPK8IP3 in 13 unrelated individuals presenting with an overlapping phenotype of mild to severe intellectual disability.
A female patient with retinoblastoma and severe intellectual disability carrying an X;13 balanced translocation without rearrangement in the RB1 gene: a case report.
De novo CLTC variants are associated with a variable phenotype from mild to severe intellectual disability, microcephaly, hypoplasia of the corpus callosum, and epilepsy.
We report on the detailed clinical characterization of a large cohort of individuals with an ADNP mutation and demonstrate a distinctive combination of clinical features, including mild to severe intellectual disability, autism, severe speech and motor delay, and common facial characteristics.
A recurrent de novo missense pathogenic variant in SMARCB1 causes severe intellectual disability and choroid plexus hyperplasia with resultant hydrocephalus.
Truncating mutations in the last and penultimate exons of the PPM1D gene were recently described as a cause for mild to severe intellectual disability in fourteen patients.
We highlight the findings in two affected siblings with splice altering variants in ALG14 and propose a new clinical entity, which includes severe intellectual disability, epilepsy, behavioral problems and mild dysmorphic features, caused by biallelic variants in ALG14.
Recently, a de novo candidate mutation (p.Arg292Pro) in the gamma isoform of CAMK2 (CAMK2G) was identified in a patient with severe intellectual disability (ID), but the mechanism(s) by which this mutation causes ID is unknown.
We herein report the first north Han Chinese patient with CIPA who exhibited classic phenotypic features and severe intellectual disability caused by a homozygous c.851-33T>A mutation of NTRK1, resulting in aberrant splicing and an open reading frame shift.
Here we report on 17 individuals from four unrelated families affected by mild to severe intellectual disability due to OPHN1 mutations without cerebellar anomaly on brain MRI.
Biallelic mutations in IBA57 cause a mitochondrial disorder with a broad phenotypic spectrum that ranges from severe intellectual disability to adolescent-onset spastic paraplegia.
Pathogenic variants in DNM1 have been implicated in global developmental delay (DD), severe intellectual disability (ID), and notably, epileptic encephalopathy.
We report a novel heterozygous CIP2Ap.D269V mutation via whole exome sequencing in two siblings with DWV and severe intellectual disability who were born to non-consanguineous parents.
Molecular anomalies in MED13L, leading to haploinsufficiency, have been reported in patients with moderate to severe intellectual disability (ID) and distinct facial features, with or without congenital heart defects.
We identified a novel mutation in ASH1L in a patient with severe intellectual disability, growth failure, microcephaly, facial dysmorphism, myelination delay, and skeletal abnormalities.
Our findings imply that microcephaly is a variable phenotype in WDR73-related disease, suggest WDR73 to be a candidate gene of severe intellectual disability and cerebellar hypoplasia, and expand the molecular spectrum of WDR73-related disease.
Published studies have indicated that cognitive functioning of individuals with MAP2K1 mutations can range from severe intellectual disability to mildly below average.