These target loci with A·T to G·C conversion in Dmd (T279A), Otc (D175G, M1V), and Sod1 (I151T, H46R) have been reported to cause X-linked dilated cardiomyopathy (XLCM)30, ornithine transcarbamylase deficiency (OTCD)31, and amyotrophic lateral sclerosis (ALS)32,33, respectively. The gene discussed is OTC; the disease is amyotrophic lateral sclerosis.