How much does mitochondrial dysfunction affect male infertility?

Infertility is usually defined as the inability of a couple to conceive even after 1 year of unprotected, frequent sexual intercourse. The male is solely responsible in about 20% of cases. Several risk factors as well as urogenital abnormalities,endocrinological disease,enviromental toxines,genetic disorders,immunological factors,urogenitaly infections,sexual dysfunction  have been identified as causes of male infertility. Nowadays different studies reported mithocoldrial dysfunction as cause of male infertility and alteration of semen parameters.