Gene Discovery Could Lead to a Male Oral Contraceptive

“A newly discovered genetic abnormality that appears to prevent some men from conceiving children could be the key for developing a male contraceptive, according to University of Iowa researchers reporting their findings in the April 2 online edition of the American Journal of Human Genetics”

The female oral contraceptive has been readily available to women for over 40 years and has been proven to be highly effective (when used correctly) in the planning of pregnancies. The only contraceptives available for men are condoms or a vasectomy and currently no male oral contraceptive (M.O.C) exists, however recent research has proven that one may be on the way.

Researchers have identified a gene that is involved in non-syndromic male infertility in humans, which could lead to the development of a M.O.C. The gene itself was hypothesised while the team’s research on Iranian families focused on identifying genetic causes of deafness, and from the collected information of the population it identified two families where male infertility appeared to be inherited.

Using lab mice and focusing on a group of genes that have been implicated in male mice infertility, the researchers discovered that mutations had occurred in the two Iranian families in the gene CATSPER1. DNA analysis however revealed two different mutations, one in each family, with one mutation producing a non-functional protein and the other not producing any at all. Neither mutation was found in the DNA of 576 Iranian men who were screened as controls.

Studies on mice that lack the CATSPER1 gene undertaken at Harvard University have revealed how sperm is affected when the protein is missing or abnormal. The studies have shown that the sperm affected by the mutation of CATSPER1 appear to have motility difficulties, namely the hyperactive motion the sperm uses during fertilization. The research goes on to suggest that this result will also be seen in humans. Further studies have shown that CATSPER1 gene is specific to sperm and therefore potentially minimising the side effects of any drug designed to affect the function of the protein being produced.

Several approaches to M.O.C are being undertaken at other institutions, with one approach displaying particular prevalence. Immunocontraception is where antibodies are developed that bind to the targeted protein produced by CATSPER1 and block its function. This method is in the early stages of development and in order to be useful must be proven to be safe, effective and reversible. If a M.O.C is developed and has been proven to possess these features, would men want to take it? According to surveys conducted by the Medical Research Council Reproductive Biology Unit in the U.K, men would be willing to use a pharmacological oral contraceptive if there was one readily available.

Student 41216747

Dr. Clare Rudkin (P11)

Reference:

University of Iowa (2009, April 10), Gene Discovery Could Lead To Male Contraceptive, ScienceDaily, Retrieved April 30, 2009, from

http://www.sciencedaily.com/releases/2009/04/090402124255.htm