Mutations in certain genes in men lead to the infertility seen in the disease asthenozoospermia. They are the reason why the sperms are damaged and cannot move efficiently towards the eggs. The condition asthenozoospermia is characterized by reduced sperm motility, which significantly reduces male fertility. Many factors can affect male infertility, including age, nutrition and even mental health. Asthenozoospermia is the leading cause of infertility in men, and it turns out that the cause of the condition lies in the genetic makeup. Multiple genetic factors have been identified that may increase the risk of asthenozoospermia. The movement of a sperm is guided by the beating of their flagella. The beating process of these flagella uses energy that comes mostly from adenosine triphosphate, a substance that is produced in the flagella. With damage to this process in the flagella, the sperm are unable to move efficiently and often cannot reach the egg during fertilization attempts. It turns out that this process is affected by certain gene mutations. These mutations affect the AK9 gene. This gene, as far as the sperm is concerned, provides certain phosphate groups that are converted into substances that the flagella use for energy. Mutations in this gene that impair this ability thus also affect motility. Deactivation of this gene was found to directly lead to sterility, or more specifically, reduced sperm motility. Although infertility depends on cell motility problems, the condition asthenozoospermia does not affect the sperm count itself. Infertility is when there is no fertilization of eggs within 12 months or more during regular sexual intercourse. Such a disability can seriously affect family and social life, and according to data from the World Health Organization, one in six people has some problem with the reproductive system. In the male reproductive system, infertility can be expressed by problems with ejaculation, no or low sperm counts, changes in sperm shape, or problems with sperm movement, such as asthenozoospermia. Asthenozoospermia is the leading cause of infertility in men, with others possible: azoospermia (absence of sperm) and oligospermia (low sperm count). References: Sha, Y. (2023, September 13) Deficiency in AK9 causes asthenozoospermia and male infertility by destabilizing sperm nucleotide homeostasis. Retrieved 2023, September 19 from https://doi.org/10.1016/j.ebiom.2023.104798