MT-ND4 and polycystic ovary syndrome: Several variants differentiating the PCOS + HT group from PCOS and controls were identified, located both in the mitochondrial genes (including the <i>MT-CYB</i>, <i>MT-ND1</i>, <i>MT-ND2</i>, <i>MT-ND4</i>, <i>MT-ND6</i>, <i>MT-CO1</i>, <i>MT-CO3</i>) and the D-loop region.