Effects of Y chromosome Microdeletions on Male Fertility

In the process of human reproduction, spermatogenesis is one of the most important stages,which is controled by special genes on Y chromosome. Previous studies show that some infertile men havemicrodeletions on Y chromosome, which cause the reduction of sperm count. Three prominent spermatogene-sis loci have been identified on the Y chromosome and entitled “azoospermia factors” (AZFa, b, and c). Hereby,this review article aimed to investigate the content of the Y chromosome microdeletions and their importancein male fertility.

Data and information were collected on English-language articles from PubMedand MEDLINE databases. For Persian articles, Persian-language databases, including SID Scientific Database,IranMedex Medical Articles Database, IranDoc (Iran Scientific Information and Documents Research Institute),Magiran Publication Information, and MedLib were investigated. More than 50 articles on Y chromosome mi-crodeletions and infertility published during 2000-2020 were studied.

Previous studies implicated thatY chromosome microdeletions in AZFa, AZFb, and AZFc regions are accompanied by defect in spermatogenesis,leading to oligo / azoospermia. Patients with AZFa and AZFb microdeletions present secretory azoospermia anddo not have sperm in their seminiferous tubules. Complete AZFc deletion involves region b2/b4, which con-tains a total of 12 genes. Incomplete deletion of AZFc includes b1/b3, b2/b3 and gr/gr. The most common ofwhich are gr/gr. In men with gr/gr deletion, sperm count and motility were lower than control group.Conclu-sion:Y chromosomal microdeletions emerged as the most frequent structural chromosome anomaly associatedwith the quantitative reduction of sperm. The development of assisted reproductive techniques (ART) like intra-cytoplasmic sperm injection (ICSI) and testicular sperm extraction (TESE) helps to bypass the natural barriersof fertilization.