Abstract

The unorthodox genetics of the mtDNA is providing new perspectives on the etiology of the common “complex ” diseases. The maternally inherited mtDNA codes for essential energy genes, is present in thousands of copies per cell, and has a very high mutation rate. New mtDNA mutations arise among thousands of other mtDNAs. The mechanisms by which these “heteroplasmic ” mtDNA mutations come to predominate in the female germline and somatic tissues is poorly understood, but essential for understanding the clinical vari-ability of a range of diseases. Maternal inheritance and heteroplasmy also pose major chal-lengers for the diagnosis and prevention of mtDNA disease.