ALDH5A1 and succinic semialdehyde dehydrogenase deficiency: As an example, we will examine succinic semialdehyde dehydrogenase deficiency (SSADHD; MIM# 271980), also known as 4-Hydroxybutyric aciduria, a rare inborn error of metabolism associated with mutations in Locus ALDH5A1 (ALDH5A1; MIM# 610045).