Mitochondrial macro-haplogroup JT may play a protective role in ovarian ageing.

This study of 200 Caucasian women shows that the distribution of the mtDNA macro-haplogroups in patients with diminished ovarian reserve (DOR) differed significantly from that of patients with normal ovarian reserve (NOR) (p=0.02). The JT macro-haplogroup was significantly under-represented in DOR patients compared with NOR patients (p=0.006) and compared with the estimated frequency of 18.8% in the general French population (p=0.0012). Our findings suggest that the risk of a prematurely depleted ovarian reserve would be three times lower for patients carrying the JT macro-haplogroup than for patients with any of the other mtDNA haplogroups (odds ratio: 0.3; 95% CI: 0.13-0.74). If these preliminary results are confirmed in larger independent studies, they should lead to the better management of infertility.