Interestingly, two mutations affecting AP4M1 and AP4E1 have recently been found to cause cerebral palsy associated with severe intellectual disability.
Interestingly, two mutations affecting AP4M1 and AP4E1 have recently been found to cause cerebral palsy associated with severe intellectual disability.
Microarray-based comparative genomic hybridization analysis identified a 737-kb microdeletion of Xq11.1, including the cell division cycle 42 guanine nucleotide exchange factor (GEF)-9 gene (ARHGEF9), encoding collybistin, which has a pivotal role in formation of postsynaptic glycine and γ-aminobutyric acid receptor clusters, in a male patient with severe mental retardation and epilepsy.
Mutations or disruption of ARHGEF9 due to chromosomal rearrangements have been found in three patients with various clinical presentations: nevertheless, all 3 presented with MR and 2 with epilepsy.
Phenotype-genotype comparison of the translocation patient to seven unpublished patients with various sized deletions encompassing ARID1B confirms that haploinsufficiency of ARID1B is associated with CC abnormalities, intellectual disability, severe speech impairment, and autism.
The multitude and diversity of known ASD genes has extended the clinical notion that ASD comprises very heterogeneous conditions ranging from severe intellectual disabilities to mild high-functioning forms.
Mutations in the CDKL5 gene (also known as STK9) have recently been shown to cause early onset epilepsy and severe mental retardation (ISSX or West syndrome).
We identified a novel mutation in ASH1L in a patient with severe intellectual disability, growth failure, microcephaly, facial dysmorphism, myelination delay, and skeletal abnormalities.
Germline de novo truncating variants in ASXL1 and ASXL3 have been respectively implicated in causing Bohring-Opitz and Bainbridge-Ropers syndromes, which result in overlapping features of severe intellectual disability and dysmorphic features.