ABSTRACT

Diabetes mellitus is a disease resulting from a variety of genetic abnormalities and environmental factors that generate a common phenotype of hyperglycemia. Type-1 diabetes (T1DM) and type-2 diabetes (T2DM) result from nuclear genomic mutations, and transmission depends on maternal 222and paternal genotypes according to Mendelian genetics. “Mitochondrial diabetes” (MTDM) results from mutations in both the nuclear genome (Mendelian genetics) and the mitochrondrial genome which are inherited primarily as a maternal trait [1]. Almost no paternal mitochondrial DNA (mtDNA) is inherited, since sperm mitochondria are localized in the tail and disappear during fertilization. Identical twins do not manifest concordance in mtDNA mutations because there is unequal distribution of mitochondria during meiosis. Depending on ethnicity, up to 10% of patients with T2DM have MTDM, and the phenotype depends on how many mutated mitochondria are present [2,3].