RABGAP1-related neurodevelopmental disorder is a rare autosomal recessive disorder caused by biallelic loss-of-function variants in RABGAP1. The disorder was first described in 2022 in five individuals from three unrelated families. Reported features include severe global developmental delay/intellectual disability, microcephaly, bilateral sensorineural hearing loss, seizures, and characteristic brain MRI abnormalities, including delayed myelination, reduced white matter volume, thinning of the corpus callosum and ventriculomegaly. Other reported features include abnormalities of muscle tone and characteristic facial features.
The prevalence is unknown. Because only a small number of individuals have been reported, the full clinical spectrum and natural history remain to be established.
The disorder follows an autosomal recessive inheritance pattern. Parents of an affected individual are typically unaffected carriers. For carrier parents, each pregnancy has a 25% chance of being affected, a 50% chance of being an unaffected carrier, and a 25% chance of being unaffected and not a carrier.
RABGAP1