Variants of the ALDH5A1 gene (6p22.3, GRCh38.p13: 24,494,969–24,537,207) are known to cause a loss of function of the mitochondrial succinic semialdehyde dehydrogenase (SSADH) and were identified in 1981 to be the underlying cause of SSADHD [1]. This evidence concerns the gene ALDH5A1 and succinic semialdehyde dehydrogenase deficiency.