ABSTRACT
Background: Y chromosome deletions [YCDs] in azoospermia factor [AZF] region are associated with abnormal spermatogenesis and may lead to azoospermia or severe oligozoospermia. Assisted reproductive tech- nologies [ART] by intracytoplasmic sperm injection [ICSI] and testicular sperm extraction [TESE] are commonly required for infertility management of patients carrying YCDs. The aim of this study was to estimate the frequency of YCDs, to find the most frequent variant in infertile men candidate for ART and to compare YCD distribution with a control fertile group. The semen parameters, hormonal profiles and ART outcomes of the infertile group were studied
Materials and Methods: This case-control study consisted of 97 oligozoospermic or non-obstructive azoospermic [NOA] infertile men, who had undergone ART, as the case group and 100 fertile men as the control group. DNA samples were extracted from blood samples taken from all 197 participants and YCDs were identified by multiplex polymerase chain reaction [PCR] of eight known sequence-tagged sites. The chi-square test was used to compare the mean values of hormone and sperm parameters between the two groups. P<0.05 was considered statistically significant
Results: No YCD was detected in the control group. However, 20 out of 97 [20.6%] infertile men had a YCD. AZFc, AZFbc and AZFabc deletions were detected in 15 [75%], four [20%] and one [5%] YCD-positive patients. No fertilization or clinical pregnancy was seen following ICSI in this sub-group with YCD. The mean level of FSH was significantly higher in the group with YCD [28.45 +/- 22.2 vs. 4.8 +/- 3.17 and 10.83 +/- 7.23 in YCD-negative patients with and without clinical pregnancy respectively]
Conclusion: YCD is frequent among NOA men and YCD screening before ART and patient counseling is thus strongly recommended
ABSTRACT
Unlike the somatic cells, sperm DNA is very compact due to replacement of histones with protamines. Disulfide bridges formed within and between the protamines inhibit the extraction of sperm DNA through standard techniques used for the somatic cells. Furthermore, the spermatozoa themselves are protected by a membrane which is rich in disulfide bonds, making cell lysis very difficult. Following a comprehensive literature search, we developed a protocol for DNA extraction from sperm and semen fluid. The quality of extracted DNA was checked running on agarose gel, used for bisulfite conversion and PCR amplification