Maternally inherited diabetes and deafness (MIDD) is another mitochondrial disease frequently associated with the m.3243 A > G mutation in the MT-TL1 gene.267 The most prominent clinical features of MIDD are diabetes and hearing loss,268 although other complications such as myopathy, neuropathy, oculopathy, cardiac disease, and nephropathy are also observed.269 Approximately 85% of MIDD cases are caused by the m.3243 A > G point mutation.269 Notably, this same mutation is also responsible for MELAS. This evidence concerns the gene MCAT and maternally-inherited diabetes and deafness.