Polycystic ovary syndrome (PCOS) is a very prevalent endocrine disease affecting reproductive women. Clinically, patients with this disorder are more vulnerable to develop type 2 diabetes mellitus (T2DM), cardiovascular events, as well as metabolic syndrome (MetS). To date, the molecular mechanism underlying PCOS remains largely unknown. Previously, we showed that mitochondrial dysfunction caused by mitochondrial DNA (mtDNA) mutation was an important cause for PCOS. In the current study, we described the clinical and biochemical features of a three-generation pedigree with maternally transmitt...