De novo STXBP1 mutations in mental retardation and nonsyndromic epilepsy

Original research article by Hamdan et al. (2009).

Read the abstract here.

Genetic testing (exome or panel sequencing) was completed for 95 individuals diagnosed with intellectual disability (ID), without growth abnormalities or specific dysmorphic features. From this group of 95 patients, researchers were able to identify 2 de novo mutations (gene changes not found in either parent) in the STXBP1 gene. Both patients were reported to be diagnosed with severe ID, epilepsy (with the first seizures occurring at 6 weeks of age and at almost 3 years of age, respectively), muscle weakness (hypotonia) and tremors. Brain imaging for both individuals was reported as normal. Later, the study expanded to include sequencing results from 142 individuals with autism spectrum disorder (ASD) as well as 190 health individuals. No STXBP1 mutations were found in either of these groups, suggesting that mutations in STXBP1 are associated with ID and non-syndromic epilepsy.