All reported children were born to parents who are related to each other. In this study, all affected individuals had harmful changes in both copies of the GAD2gene. These included two changes that introduce an early stop signal in the gene (p.Gln548* and p.Arg375*) and one change that disrupts normal gene processing (c.137-2A>G). Our showed that all of these changes lead to a shortened, non-working protein. Other types of changes affecting both copies of GAD2have also been reported in the scientific literature, but there is currently not enough clinical or experimental evidence to confirm whether they cause disease.
GAD2