Michael Hildebrand, PhD, of the University of Iowa’s department of otolaryngology, spoke with WebMD about the CATSPER1 gene mutations linked to male infertility – and the possibility of a male contraceptive based on the CATSPER1 gene. Here are excerpts from his comments to WebMD.
If we were to develop any therapy for people with infertility or if we were to consider male contraceptives, in either of those cases, we would still need to do studies in animal models to make sure the approach is both safe and effective — and only then could we test it in humans.
It would probably take at least a couple of years to complete the animal studies, and then it would be additional years beyond that for clinical trials.
Our laboratory focuses on genetic disease — typically hearing loss, but we also study families with other problems as well.
In this particular case, we identified two families in which multiple male individuals had infertility problems, and so we took those two families and we identified the gene that was underlying their infertility.
This was a sperm-specific gene; it’s a calcium channel that’s really essential for the normal movement of the sperm. We also had the advantage of previous studies that have been published which had shown that mice deficient for this particular protein had infertility.
One key [next] step is to investigate additional families to see if they have similar mutations affecting the same gene. We potentially could screen the other three genes [related to CATSPER1] in additional families, as well.
Also, there’s been some preliminary work done looking at using antibodies as a potential contraceptive device in males, and there’s been one study with specifically this CATSPER1 protein and have shown, in the laboratory, that both human and mice sperm treated with this particular antibody… [are] associated with reduced fertility — those sperm are not as able to fertilize an egg, at least not in a laboratory.
One problem with infertility is it’s often difficult to determine the cause — whether it’s related to the male or the female member of the couple, and what the underlying cause is. So there [are] potentially other genes which haven’t been identified.
There are other situations where the deletion of multiple genes is associated with infertility as well as other clinical presentations, but there [are] only a few which are just associated with infertility and are presumably due to proteins which are specifically expressed in the sperm.
Read the WebMD news story about the CATSPER1 gene study.