A missense and silent mutation on the human 17β-HSD10 gene results in 2-methyl-3-hydroxybutyryl-CoA dehydrogenase/HSD10 deficiency with developmental disabilities [32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49] and mental retardation, choreoathetosis, and abnormal behavior (MRXS10) [60,61], respectively. This evidence concerns the gene HSD17B10 and developmental disability.