Genetic causes of male infertility and molecular biology

At the present time, 15% of couples experience reproduction difficulties. Surgical collection of spermatozoa associated with the intracytoplasmic sperm injection technique (ICSI) resolves the problems of male infertility formerly considered to be irreversible, regardless of its aetiology. Molecular biology now allows evaluation of the genetic dimension of male infertility. Although it demonstrates the multiple aetiologies of male infertility, it also reveals the gaps in our knowledge and the extent of the task that has yet to be accomplished. Microdeletion of the Y chromosome, detected in 2% to 20% of infertile patients with a disorder of spermatogenesis, has already been well documented. All of the genes involved on the Y chromosome (DAZ, RBMY etc.) in infertile patients have been shown to be involved in spermatogenesis. Testing for other genes of the genome would also be useful. However, the unknown outcome of these abnormalities with successive generations raises a number of questions. In this article, the authors describe the main genes involved in spermatogenesis as demonstrated by molecular biology.