Globozoospermia

Globozoospermia
Other namesRound-headed sperm syndrome[1]
Figure 1: Diagram representing the morphology of normal sperm. Areas surrounded by an orange box represent areas changed in the sperm of an individual with globozoospermia. Orange boxes highlight the specifics of the changed areas in globozoospermia.

Globozoospermia is a rare and severe form of monomorphic teratozoospermia. This means that the spermatozoa show the same abnormality, and over 85% of spermatozoa in sperm have this abnormality.[1] Globozoospermia is responsible for less than 0.1% of male infertility.[2] It is characterised by round-headed spermatozoa without acrosomes, an abnormal nuclear membrane and midpiece defects.[1] Affected males therefore suffer from either reduced fertility or infertility.[2] Studies suggest that globozoospermia can be either total (100% round-headed spermatozoa without acrosomes) or partial (20-60% round acrosomeless spermatozoa with normal sperm also identified in the sperm count),[3] however it is unclear whether these two forms are variations on the same syndrome, or actually different syndromes.[2]

Infertility in this condition results from the sperm heads missing their acrosome. These sperm, therefore, have a characteristic round or spherically shaped head. Given the absence of the acrosome, these sperm are unable to penetrate the oocyte and are unable to achieve fertilization through conventional means; however, these sperm are able to fertilize the egg through in vitro fertilization with intracytoplasmic sperm injection, which is the treatment of choice for these patients.[4]

Studies have suggested mutations or deletions in three genes are responsible for this condition: SPATA16, PICK1 and DPY19L2.[1] ICSI (intracytoplasmic sperm injection) has previously been used to assist reproduction in globozoospermic patients, however it has not been particularly effective in all patients, due to low fertilisation rates.[2]

  1. ^ a b c d De Braekeleer, Marc; Nguyen, Minh Huong; Morel, Frédéric; Perrin, Aurore (2015-04-01). "Genetic aspects of monomorphic teratozoospermia: a review". Journal of Assisted Reproduction and Genetics. 32 (4): 615–623. doi:10.1007/s10815-015-0433-2. ISSN 1058-0468. PMC 4380889. PMID 25711835.
  2. ^ a b c d Dam, A. H. D. M.; Feenstra, I.; Westphal, J. R.; Ramos, L.; van Golde, R. J. T.; Kremer, J. a. M. (2007-02-01). "Globozoospermia revisited". Human Reproduction Update. 13 (1): 63–75. doi:10.1093/humupd/dml047. ISSN 1355-4786. PMID 17008355.
  3. ^ Cite error: The named reference :3 was invoked but never defined (see the help page).
  4. ^ Meacham RB, Chemes H, Carrell D, Goldstein M (2007). "Globozoospermia: is there a role for varicocele repair?". J Androl. 28 (4): 490. doi:10.2164/jandrol.107.002907. PMID 17460092.{{cite journal}}: CS1 maint: multiple names: authors list (link)