Department of Zoology, Faculty of Science, University of Khartoum, P.O. Box 321, 11115, Khartoum, Sudan.
Elsir Abu Alhassan Fertility Centre, Khartoum, Sudan.
BMC Urol. 2021 Apr 23;21(1):69. doi: 10.1186/s12894-021-00834-3.
Male factor is the major contributor in roughly half of infertility cases. Genetic factors account for 10-15% of male infertility. Microdeletions of azoospermia factors (AZF) on the Yq region are the second most frequent spermatogenesis disorder among infertile men after Klinefelter syndrome. We detected in our previous study a frequency of 37.5% AZF microdeletions which investigated mainly the AZFb and AZFc. We attempted in this study for the first time to evaluate the frequencies of all AZF sub-regions microdeletions and to analyze reproductive hormonal profiles in idiopathic cases of azoospermic and oligozoospermic men from Sudan.
A group of 51 medically fit infertile men were subjected to semen analysis. Four couples have participated in this study as a control group. Semen analysis was performed according to WHO criteria by professionals at Elsir Abu-Elhassan Fertility Centre where samples have been collected. We detected 12 STSs markers of Y chromosome AZF microdeletions using a multiplex polymerase chain reaction. Analysis of reproductive hormone levels including Follicle Stimulating, Luteinizing, and Prolactin hormones was performed using ELISA. Comparisons between outcome groups were performed using Student's t-test Chi-square test or Fisher's exact test.
AZF microdeletion was identified in 16 out of 25 Azoospermic and 14 out of 26 of the Oligozoospermic. Microdeletion in the AZFa region was the most frequent among the 30 patients (N = 11) followed by AZFc, AZFd (N = 4 for each) and AZFb (N = 3). Among the Oligozoospermic participants, the most frequent deletions detected were in the AZFa region (N = 10 out of 14) and was significantly associated with Oligozoospermic phenotype, Fisher's Exact Test (2-sided) p = 0.009. Among the Azoospermic patients, the deletion of the AZFc region was the most frequent (N = 9 out of 16) and was significantly associated with Azoospermia phenotype Fisher's Exact Test p = 0.026. There was a significant difference in Y chromosome microdeletion frequency between the two groups. The hormonal analysis showed that the mean levels of PRL, LH, and FSH in Azoospermic patients were slightly higher than those in oligozoospermic. A weak negative correlation between prolactin higher level and Azoospermic patients was detected. (AZFa r = 0.665 and 0.602, p = 0.000 and 0.0004, AZFb r = 0.636 and 0.409, p = 0.000 and 0.025, and AZFd r = 0.398 and 0.442, p = 0.029 and 0.015). The correlation was positive for AZFa and negative for AZFb and AZFd.
We concluded in this study that the incidences of microdeletions of the Y chromosome confined to AZF a, b, c and d regions is 58.8% in infertile subjects with 31.4% were Azoospermic and 27.5% were Oligozoospermic. This might provide a piece of evidence that these specified regions of the Y chromosome are essential for controlling spermatogenesis. These findings will be useful for genetic counseling within infertility clinics in Sudan and to adopt appropriate methods for assisted reproduction.
男性因素是大约一半不孕病例的主要原因。遗传因素占男性不育的 10-15%。Y 染色体无精子因子(AZF)微缺失是除克氏综合征外导致男性不育的第二大常见精子发生障碍。我们在之前的研究中发现,37.5%的 AZF 微缺失主要发生在 AZFb 和 AZFc 区域。我们首次尝试评估所有 AZF 亚区微缺失的频率,并分析来自苏丹的特发性无精子症和少精子症男性的生殖激素谱。
一组 51 名医学上适合的不育男性接受了精液分析。四对夫妇作为对照组参与了这项研究。精液分析由专业人员按照世卫组织标准在 Elsir Abu-Elhassan 生育中心进行,样本在此收集。我们使用多重聚合酶链反应检测 Y 染色体 AZF 微缺失的 12 个 STS 标记。使用 ELISA 检测包括卵泡刺激素、黄体生成素和催乳素在内的生殖激素水平。使用学生 t 检验、卡方检验或 Fisher 确切检验比较结果组之间的差异。
在 25 名无精子症和 26 名少精子症患者中,有 16 名和 14 名分别检测到 AZF 微缺失。在 30 名患者中(N=11),最常见的缺失是 AZFa 区,其次是 AZFc、AZFd(各 N=4)和 AZFb(各 N=3)。在少精子症患者中,最常见的缺失是 AZFa 区(N=14 例中的 10 例),与少精子症表型显著相关,Fisher 确切检验(双侧)p=0.009。在无精子症患者中,AZFc 区的缺失最为常见(N=16 例中的 9 例),与无精子症表型显著相关,Fisher 确切检验 p=0.026。两组间 Y 染色体微缺失频率存在显著差异。激素分析显示,无精子症患者的催乳素、LH 和 FSH 水平略高于少精子症患者。检测到催乳素水平升高与无精子症患者呈弱负相关。(AZFa r=0.665 和 0.602,p=0.000 和 0.0004,AZFb r=0.636 和 0.409,p=0.000 和 0.025,AZFd r=0.398 和 0.442,p=0.029 和 0.015)。相关性为 AZFa 为正,AZFb 和 AZFd 为负。
本研究发现,Y 染色体局限于 AZF a、b、c 和 d 区的微缺失发生率为 58.8%,其中 31.4%为无精子症,27.5%为少精子症。这可能为 Y 染色体特定区域对控制精子发生至关重要提供了证据。这些发现将有助于在苏丹的不孕不育诊所进行遗传咨询,并采用适当的辅助生殖方法。