Severe oligozoospermia- Less than 5 × 10 6 spermatozoa in the ejaculate Oligozoospermia- Less than 15–20 × 10 6 spermatozoa in the ejaculate NOA constitutes 60% of all cases of azoospermia As per WHO 2010 male infertility can be classified based on seminogram under following categories:Īzoospermia- Absence of sperm in the ejaculate, it can be classified as obstructive azoospermia where absence of sperm in the ejaculate is observed as a result of problems in sperm delivery or non-obstructive azoospermia where there is absence of sperm in the semen due to abnormal sperm production. Almost 30 million males worldwide are infertile with the largest niches of male infertility occurring in central and Eastern Europe and Australia. According to the World Health Organization, male infertility refers to the inability of the male partner to cause pregnancy in a clinically normal female. Defects at any of these levels can lead to accumulation of errors resulting in impaired spermatogenesis leading to male infertility. The spermatogenic process relies on the concerted actions of various hormones, local secretory factors and testis-specific genes. After a second meiosis cycle, these secondary spermatocytes produce haploid cells called round spermatids, which subsequently form elongated spermatids which finally differentiate into mature spermatozoa. Human spermatogenesis is an intricate biological process that begins with the mitotic division of spermatogonia to give rise to primary spermatocytes which in turn undergo the first meiotic division to form secondary spermatocytes. If found so, the information will change the current the perspective of androgenetics from infertility and might have broad implication in men health. With the emerging data on association of Yq deletions with testicular cancers and neuropsychiatric conditions long term follow-up data is urgently needed for infertile men harboring Yq deletions. As these deletions are transmitted to 100% of male offspring born through assisted reproduction, testing of Yq deletions will allow the couples to make an informed choice regarding the perpetuation of male infertility in future generations. Clinically, the screening for Yq microdeletions would aid the clinician in determining the cause of male infertility and decide a rational management strategy for the patient. Analysis of > 17,000 Y chromosomes from fertile and infertile men has revealed an association of gr/gr deletion with male infertility in Caucasians and Mongolian men, while the b2/b3 deletion is associated with male infertility in African and Dravidian men. In addition, partial deletions of the AZFc locus have been associated with infertility but the effect seems to be ethnicity dependent. As estimated from data of nearly 40,000 Y chromosomes, the global prevalence of Yq microdeletions is 7.5% in infertile males however the European infertile men are less susceptible to Yq microdeletions, the highest prevalence is in Americans and East Asian infertile men. Three common Yq deletions that recur in infertile males are termed as AZF (Azoospermia Factor) microdeletions viz. Such deletions lead to copy number variation in genes of the Y chromosome resulting in male infertility. The long arm of the Y chromosome (Yq) contains many ampliconic and palindromic sequences making it predisposed to self-recombination during spermatogenesis and hence susceptible to intra-chromosomal deletions. The human Y chromosome harbors genes that are responsible for testis development and also for initiation and maintenance of spermatogenesis in adulthood.
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