This makes the sperm completely unable to penetrate the zona pellucida. The sperm in Type 2 globozoospermia has some acrosomal covering surrounded by large droplets of cytoplasmic material, suggesting secondary degenerative changes. There is also a conical nucleus. It is thought that infertility in this type of globozoospermia is due to incorrect chromatin packaging which prevents proper fertilization. Symptoms
Aside from the effect on fertility globozoospermia is symptomless. People with globozoospermia have normal physical and mental development, normal clinical features and normal hormonal profile. Genetics
Table 1: Gene mutations that have been identified in globozoospermia and the impact these mutations have on sperm function and successful fertilization. Diagnosis
The presence of round headed sperm in a semen analysis sample confirms the diagnosis of globozoospermia. The lack of acrosome can be ascertained by either morphology staining or immunofluorescence. Treatment
Until 1995, the only options for people with globozoospermia who wished to conceive were adoption or sperm donation. With the advancement of assisted reproductive techniques (ART) it is now possible for those with globozoospermia to conceive using their own sperm. The main technique used is intracytoplasmic sperm injection (ICSI) where fertilisation is achieved by a single sperm being injected into the egg. Some studies have shown it is possible for a viable embryo to be created with this technique alone, however others have found it necessary to also use calcium ionophore treatment for fertilisation to be successful. Calcium ionophore treatment is used to artificially activate the oocyte.
Another promising treatment area also looks at causing oocyte activation in conjunction with ICSI, this time using spermatic binding-proteins, phospholipase C zeta (PLCζ) and postacrosomal sheath WW domain binding protein (PAWP). == References ==