All reported individuals were born to consanguineous parents. All affected individuals in this study carried homozygous pathogenic GAD2variants, including two nonsense variants (p.Gln548* and p.Arg375*), as well as one intronic splice-acceptor site variant (c.137-2A>G). Based on our functional analyses, all variants resulted in truncated protein products. Bi-allelic missense variants have been reported in the literature, only with insufficient clinical and functional data.
GAD2