TRPM3-related neurodevelopmental disorder

TRPM3-related neurodevelopmental disorder is a single-gene developmental and epileptic encephalopathy that affects the central nervous system. Its range of features includes global developmental delay, intellectual disability, epilepsy (reported in about half of cases), low muscle tone from birth, ataxia, nystagmus, cerebellar atrophy, musculoskeletal differences such as scoliosis and hip dysplasia, and altered pain perception. It is an autosomal dominant condition caused by missense mutations in the TRPM3 gene, and research indicates the mutations increase the activity of the TRPM3 ion channel, a gain of function. Diagnosis uses a multigene panel or exome sequencing that includes TRPM3, followed by tests of channel activity. There is no known cure; symptoms are managed with standard care such as antiseizure medication and physical, occupational and speech therapy, and one study points to the drug primidone, a TRPM3 antagonist, as an off-label option. About fifty cases have been reported and life span appears unaffected.