Intellectual disability without epilepsy associated with STXBP1 disruption
Original research article by Hamdan et al. (2011).
Read the abstract here.
Following up on their previous research (Hamdan et al., 2009), Dr. Hamdan and his team sequenced samples from 50 new individuals with non-syndromic intellectual disability (NSID). They identified one 21-year-old individual with a de novo mutation (not found in either parent) in the STXBP1gene. Unlike their previous findings (where two individuals were reported to have non-specific epilepsy were found to have STXBP1 mutations), the newly identified individual did not have a reported history of epilepsy. He was reported to have a diagnosis of severe intellectual disability (ID), but had no history abnormal EEGs or brain imaging. The individual did not experience any muscle weakness (hypotonia), but did have a history of tremors. This finding supports the idea that the STXBP1 gene may be linked to a wider range or spectrum of features than previously understood.