A rare missense mutation, c.910A>G (p.K304E), of the MECP2 gene in a Thai girl with classical rett syndrome.

Rett syndrome is a severe X-linked dominant neurological disorder affecting girls almost exclusively. According to RettBASE, several common and rare mutations have been reported. Some rare variants have no clinical description and have not been categorized as polymorphism or mutation. Here, we report a rare missense, c.910A>G (p.K304E), in a 10-year-old Thai girl with classical RTT based on clinical diagnosis. Only normal A alleles were found in her parents and 500 control chromosomes. This variant has been previously reported in 2 cases with unknown clinical features and uncertain mutation/polymorphism status. Thus we confirmed that c.910A>G (p.K304E) is likely to be a rare mutation causing RTT.