Molecular study on Y chromosome microdeletions in Egyptian males with idiopathic infertility

Aim: To determine the frequency of genetic deletions within the azoospermia factors in Egyptian infertile males. Methods: The Yq microdeletions in 33 infertile males with undetectable chromosomal anomalies were examined by mutiplex polymerase chain reaction (PCR). Deletions were confirmed using single PCR amplifications. Results: Four out of the total 33 (12 %) men had Yq11 microdeletions, thus supporting the average reported figures in other populations. Three of those 4 cases had single short tandem sequence deletions with discrete histological findings of their testes. Single sY272 deletion within AZFc was associated with Sertoli cell only syndrome, whereas a patient with isolated sY84 deletion within AZFa had immature testicular structure. The remaining case had a large deletion in AZFa-c and short stature. Conclusion: The present study supports the hypothesis that the Yqn encompasses genetic determinants of stature besides genes controlling spermatogenesis.

"Micro-deletions" of the human Y chromosome and their relationship with male infertility

The Y chromosome evolves from an autochromosome and accumulates male-related genes including sex-determining region of Y-chromosome （SRY） and several spermatogenesis-related genes. The human Y chromosome （60 Mb long） is largely composed of repetitive sequences that give it a heterochromatic appearance, and it consists of pseudoautosomal, euchromatic, and heterochromatic regions. Located on the two extremities of the Y chromosome, pseudoautosomal regions 1 and 2 （PAR1 and PAR2, 2.6 Mb and 320 bp long, respectively） are homologs with the termini of the X chromosome. The euchromatic region and some of the repeat-rich heterochromatic parts of the Y chromosome are called ＂male-specific Y＂ （MSY）, which occupy more than 95% of the whole Y chromosome. After evolution, the Y chromosome becomes the smallest in size with the least number of genes but with the most number of copies of genes that are mostly spermatogenesis-related. The Y chromosome is characterized by highly repetitive sequences （including direct repeats, inverted repeats, and palindromes） and high polymorphism. Several gene rearrangements on the Y chromosome occur during evolution owing to its specific gene structure. The consequences of such rearrangements are not only loss but also gain of specific genes. One hundred and fifty three haplotypes have been discovered in the human Y chromosome. The structure of the Y chromosome in the GenBank belongs to haplotype R1. There are 220 genes （104 coding genes, 111 pseudogenes, and 5 other uncategorized genes） according to the most recent count. The 104 coding genes encode a total of about 48 proteins/protein families （including putative proteins/protein families）. Among them, 16 gene products have been discovered in the azoospermia factor region （AZF） and are related to spermatogenesis. It has been discovered that one subset of gene rearrangements on the Y chromosome, ＂micro-deletions＂, is a major cause of male infertility in some populations. However, controversies exist about different Y chromosome haplotypes. Six AZFs of the Y chromosome have been discovered including AZFa, AZFb, AZFc, and their combinations AZFbc, AZFabc, and partial AZFc called AZFc/gr/gr. Different deletions in AZF lead to different content spermatogenesis loss from teratozoospermia to infertility in different populations depending on their Y haplotypes. This article describes the structure of the human Y chromosome and investigates the causes of micro-deletions and their relationship with male infertility from the view of chromosome evolution. After analysis of the relationship between AZFc and male infertility, we concluded that spermatogenesis is controlled by a network of genes, which may locate on the Y chromosome, the autochromosomes, or even on the X chromosome. Further investigation of the molecular mechanisms underlying male fertility/infertility will facilitate our knowledge of functional genomics.

Yq AZF microdeletions in male infertility:An update on the phenotypic spectrum,epidemiology and diagnostics

According to the latest data,globally 15%of couples have infertility and male infertility contributes to 10%of all cases.Infertility can be caused by certain biological changes in the gonads and the reproductive system like azoospermia,oligospermia,asthenospermia,teratozoospermia and hypospermatogenesis.Genetic causes of azoospermia include chromosomal abnormalities,Y chromosome microdeletions and deletion or other mutations of Y-linked genes.The maximum number of the genes are located in the azoospermia factor region of the long arm(Yq)of the Y chromosome.Y chromosome microdeletion is known as the second major genetic cause of spermatogenetic failure.This article aims to review the latest updates on the involvement of Yq microdeletions in male infertility.The diagnostics,prevalence and phenotypic spectrum related to Yq gene microdeletions are discussed.

Frequency of Y chromosome microdeletions and chromosomal abnormalities in infertile Thai men with oligozoospermia and azoospermia

Aim： To investigate the possible causes of oligozoospermia and azoospermia in infertile Thai men, and to find the frequencies of Y chromosome microdeletions and cytogenetic abnormalities in this group. Methods： From June 2003 to November 2005, 50 azoospermic and 80 oligozoospermic men were enrolled in the study. A detailed history was taken for each man, followed by general and genital examinations. Y chromosome microdeletions were detected by multiplex polymerase chain reaction （PCR） using 11 gene-specific primers that covered all three regions of the azoospermic factor （AZFa, AZFb and AZFc）. Fifty men with normal semen analysis were also studied. Karyotyping was done with the standard G- and Q-banding. Serum concentrations of follicle stimulating hormone （FSH）, luteinizing hormone （LH）, prolactin （PRL） and testosterone were measured by electrochemiluminescence immunoassays （ECLIA）. Results： Azoospermia and oligozoospermia could be explained by previous orchitis in 22.3%, former bilateral cryptorchidism in 19.2%, abnormal karyotypes in 4.6% and Y chromosome microdeletions in 3.8% of the subjects. The most frequent deletions were in the AZFc region （50%）, followed by AZFb （33%） and AZFbc （17%）. No significant difference was detected in hormonal profiles of infertile men, with or without microdeletions. Conclusion： The frequencies of Y chromosome microdeletions and cytogenetic abnormalities in oligozoospermic and azoospermic Thai men are comparable with similarly infertile men from other Asian and Western countries.

The prevalence of azoospermia factor microdeletion on the Y chromosome of Chinese infertile men detected by multi-analyte suspension array technology

Aim： To develop a high-throughput multiplex, fast and simple assay to scan azoospermia factor （AZF） region microdeletions on the Y chromosome and establish the prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. Methods： In total, 178 infertile patients with azoospermia （nonobstructed）, 134 infertile patients with oligozoospermia as well as 40 fertile man controls were included in the present study. The samples were screened for AZF microdeletion using optimized multi-analyte suspension array （MASA） technology. Results： Of the 312 patients, 36 （11.5%） were found to have deletions in the AZF region. The rnicrodeletion frequency was 14% （25/178） in the azoospermia group and 8.2% （11/134） in the oligospermia group. Among 36 patients with microdeletions, 19 had deletions in the AZFc region, seven had deletions in AZFa and six had deletions in AZFb. In addition, four patients had both AZFb and AZFc deletions. No deletion in the AZF region was found in the 40 fertile controls. Conclusion： There is a high prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. The MASA technology, which has been established in the present study, provides a sensitive and high-throughput method for detecting the deletion of the Y chromosome. And the results suggest that genetic screening should be advised to infertile men before starting assisted reproductive treatments.

PCR analysis of Yq microdeletions in infertile males, a study from South India

AIM: To estimate the frequency of microdeletions in the long arm of Y-chromosome of 20 infertile males from South India. METHODS: Polymerase chain reaction (PCR) amplification using Y-specific STS of azoospermia factor (AZF) regions i.e., SY 84 for AZFa, SY 127 for AZFb and SY 254 for AZFc. RESULTS: Of the 20 infertile subjects 3 (15 %), one azoospermic and two oligozoospermic, showed microdeletions in the AZF region of Y-chromosome. CONCLUSION: The frequency of deletions involving AZF region of the Y-chromosome is 15 % in azoospermic and severely oligozoospermic infertile men. PCR amplification of AZF locus is useful for the diagnosis of microdeletions in the Y-chromosome.

Clinical and pathological correlation of the microdeletion of Y chromosome for the 30 patients with azoospermia and severe oligoasthenospermia

Aim: To review the accumulated 30 patients with different area of Y chromosome microdeletions, focusing on their correlation with the clinical and pathological findings. Methods: A total of 334 consecutive infertile men with azoospermia (218 patients) and severe oligoasthenospermia (116 patients) were screened. Complete physical and endocrinological examinations, general chromosome study and multiplex polymerase chain reaction assay to evaluate the Y chromosome microdeletion were performed. Ten patients received testicular biopsy. Then the clinical and pathological findings were analyzed with reference to the areas of Y chromosome microdeletion. Results: There is a decline of the percentage of sperm appearing in semen in the group that the gene deletion region from AZFc to AZFb. The clinical evidence of the impairment (decreased testicular size and elevated serum FSH) is also relevantly aggravated in this group. However, the pathology of testicular biopsy specimen was poorly correlated with the different deletion areas of the Y chromosome, which may be due to the limited number of specimens. Conclusion: The clinical correlation of spermatogenic impairment to the different AZF deletion regions may provide the information for the infertile couples in pre-treatment counseling.

Multiplex PCR Screening of Y Chromosome Microdeletions in Azoospermic Patients

Objective To develop a multiplex PCR protocol for routine screening of microdeletions on the Y chromosome Methods Five multiplex sets were established and Y chromosome microdeletions screening were carried out in 26 azoospermic men who undertook ICSI and 30 azoospermic men who undertook testicular biopsy. Results In 56 azoospermic men, 5 patients were found with AZFc/DAZ microdeletions, 2 patients were accompanied by AZFc/DAZ and AZFb/RBM1 double microdeletion, and 1 patient had only single sY153 microdeletion. Conclusion The multiplex PCR protocol presented in this study is an easy and reliable method for detecting microdeletions on the Y chromosome. Routine screening for microdeletions on the Y chromosome in azoospermic patients is essential.

男性不育患者Y染色体微缺失和染色体核型的研究

目的探讨男性不育患者中Y染色体微缺失、染色体核型异常与男性精液质量的关系,为男性不育患者的临床治疗和选择合理的生殖辅助技术以及优生优育提供科学依据。方法回顾性分析2019年1月至2023年12月于汕头大学医学院附属粤北人民医院生殖医学中心就诊的男性不育患者210例,分为无精子症组、严重少精子症组、少精子症组。同期36例健康男性为对照组。所有患者均进行精液常规分析,采用PCR荧光探针法进行Y染色体微缺失检测和G显带技术进行染色体核型分析。结果210例不育男性中检出11例Y染色体微缺失异常,29例染色体核型异常,染色体正常多态性3例,1例无精患者CFTR基因杂合突变。其中最常见的异常染色体核型为47,XXY,检出14例。36例健康对照组中有3例染色体正常多态性。男性不育组和健康对照组在Y染色体微缺失和染色体核型异常检出率存在显著差异。结论Y染色体微缺失和染色体核型异常是男性不育的重要因素。孕前进行遗传学检查,有助于患者诊断治疗和选择合理的生殖辅助技术,为优生优育提供科学依据。

Genetics and male infertility

The goal of this review is to explain the requirement for understanding the genetic structure of infertility arising from male factor and to discuss the essentials of these genetic elements(2). The majority of the population is affected by this disorder caused by male factor infertility(1); but the etiologies are still unknown. After the primary genetic structure in infertile phenotypes is searched, an evaluation can be made. Thus the reasons causing infertility can be discovered and patients can benefit from effective therapies(1). Publications about male infertility within the recent 10 years in the Pubmed database were discussed(1). There are some approachments for describing the function of specificgenes, but no adequate study is present to be useful for diagnosing and treating male infertility(1). Male fertility and fertility in offspring of males are considerably affected by the exact transition of epigenetic information(1). When the genetic factors playing a role in male infertility were analysed, significant steps will be taken for treating patients and determining the reasons of idiopathic infertility(1). Developments in technology associated with the impact of genetics may enable to specify the etiology of male infertility by determining specific infertile phenotype marks(1).

赤峰地区男性不育患者Y染色体微缺失的检测分析

目的:探讨赤峰地区男性不育患者Y染色体微缺失的检测效果。方法:选取2022年1月—2023年7月赤峰学院附属医院收治的男性不育患者150例为研究对象,结合诊断结果将其分为初诊不孕不育组、精子状态异常组、睾丸发育异常组,各50例。三组患者均进行Y染色体微缺失检测。比较三组检测结果。结果:睾丸发育异常组患者的Y染色体微缺失率高于初诊不孕不育组、精子状态异常组,差异有统计学意义(P<0.05)。AZFa位点、AZFb位点的缺失例数是0,AZFc位点的缺失例数是16例,AZFbc位点的缺失例数是1例,AZFabc位点的缺失例数是1例;初诊不孕不育组、精子状态异常组、睾丸发育异常组的缺失位点均以AZFc为主。结论:初诊不孕不育、精子状态异常、睾丸发育异常患者容易出现Y染色体AZFc位点缺失现象。

1338例男性无精症或少精症患者Y染色体微缺失分析

目的探讨男性无精症或少精症患者的Y染色体微缺失情况。方法1338例男性不育患者按照精液常规检查结果分为无精症组、严重少精症组、少精症组,选取同期320例健康男性为正常对照组,应用荧光定量PCR技术进行AZF区微缺失分析。结果无精症组和严重少精症组的Y染色体微缺失发生率均显著高于正常对照组(P<0.05)。在入组的研究对象中,AZFc位点缺失在男性不育中占比最高,为4.9%。在118例Y染色体微缺失患者中,共有25例染色体核型异常,其中以47,XXY核型占比最高,为8.5%。结论Y染色体微缺失检测是男性少精症或无精症等的首选临床检测项目,对男性不育的诊断有重要的指导价值。

男性不育患者Y染色体AZF区域STS微缺失位点多重PCR法检测及其意义

目的:探讨Y染色体无精子症因子(AZF)区域的15个标签位点(STS)序列片段微缺失位点与男性不育(MI)的关系,为干预遗传性MI提供依据。方法:选择2 586例疑似MI患者作为研究对象,按照年龄分为≤20岁组(14例)、21~30岁组(988例)、 31~40岁组(1 318例)和≥41岁组(266例)。采用聚合酶链式反应(PCR)法对Y染色体AZF区域的15个STS序列片段进行检测并筛选异常结果,比较各组MI患者Y染色体微缺失情况。结果:在2 586例参检人群样本中发现207例Y染色体异常,占总体样本的8.00%;其中≤20岁组、21~30岁组、31~40岁组和≥41岁组检出Y染色体异常率分别为7.14%(1/14)、8.10%(80/988)、8.04%(106/1 318)和7.52%(20/266);各组患者基础位点合并扩展位点的缺失率比较差异有统计学意义(χ^(2)=10.836,P=0.013),21~30岁组患者基础位点合并扩展位点的缺失率明显高于31~40岁组(P<0.05);在总体受检样本中,发生基础位点片段缺失者52例,异常率为2.01%,各组患者异常率比较差异有统计学意义(χ^(2)=9.658,P=0.022);AZFc片段缺失者占所有受检人数1.39%,21~30岁组和31~40岁组患者AZFc缺失率明显高于≥41岁组(P<0.05),21~30岁组和31~40岁组患者总体缺失率比较差异有统计学意义(χ^(2)=3.612, P=0.040);各组患者sY127、 sY134合并sY105、 sY121、 sY1192、 sY153和sY160位点缺失率比较差异无统计学意义(P>0.05),各组患者sY254、sY255合并sY105、sY121、sY1192、sY153和sY160位点缺失率比较差异无统计学意义(P>0.05)结论:广西壮族自治区东北部地区主要生育年龄段男性Y染色体异常的主要原因是sY1192和sY153位点微缺失,其中以sY1192位点微缺失为主,且随着年龄增长,该位点突变检出率越高。

Vertical transmission of the Yq AZFc microdeletion from father to son over two or three generations in infertile Han Chinese families

This study was carried out to analyze the vertical transmission of Yq AZFc microdeletions from father to son in infertile Han Chinese families to investigate genetic factors and family background affecting fertility status.The peripheral blood of infertile males in 19 Han families was extracted and screened with modified multiplex polymerase chain reaction （PCR）. Family trees were drawn according to fertility status and clinical characteristics of the subjects. The vertical transmission of Yq AZFc microdeletions was detected in six cases of 19 investigated families （31.6%,6/19）. Although both fathers and sons showed a similar type of Yq AZFc deletion,the fathers were fertile,whereas the sons were infertile and showed severe oligozoospermia. The vertical transmission of Yq AZFc microdeletion from fertile fathers to infertile sons over generations is not rare. This has different effects on fertility status in fathers and sons in Han Chinese families. Both genetic factors and family background affect spermatogenetic phenotypes.

Y-chromosomal microdeletions and partial deletions of the Azoospermia Factor c(AZFc)region in normozoospermic,severe oligozoospermic and azoospermic men in Sri Lanka

Aim： To assess for the first time the occurrence of Y chromosomal microdeletions and partial deletions of the Azoospermia Factor c （AZFc） region in Sri Lankan men and to correlate them with clinical parameters. Methods： In a retrospective study, we analyzed 96 infertile men （78 with non-obstructive azoospermia） and 87 controls with normal spermatogenesis. AZFa, AZFb, AZFc and partial deletions within the AZFc region were analyzed by multiplex polymerase chain reaction （PCR） according to established protocols. Results： No AZFa, AZFb or AZFc deletions were found in the control group. Seven patients in the group of infertile men were found to have deletions as following： one AZFa, two AZFc, two AZFbc and two AZFabc. The relative distribution of these patterns was significantly different compared with that found in the German population. Extension analysis confirmed that the deletions occurred according to the current pathogenic model, gr/gr deletions were found to be equally present both in the patients （n = 4） and in the control group （n = 4）. One b2/b3 deletion was found in the patient group. Conclusion： These results suggest that the frequency and pattern of microdeletions of the Y chromosome in Sri Lankan men are similar to those found in other populations and confirm that gr/gr deletions are not sufficient to cause spermatogenetic failure. （Asian J Androl 2006 Jan; 8： 39-44）

Y microdeletions in the Istria county,Croatia

Aim:To establish the frequency of Y chromosome microdeletions in an unselected group of infertile Croatian men. Methods:An unselected group of 105 patients (male partners of infertile couples),both with idiopathic and non- idiopathic infertility,consecutively referred to the outpatient infertility clinic,gynecology department,General Hospital Pula,Istria County,Croatia,was examined for the presence or absence of Y chromosome microdeletions by poly- merase chain reaction analysis.Results:One of the 105 men (0.95 %,95 % CI=0.17-5.2 %) was found to have a microdeletion.Conclusion:A low frequency of Y chromosome microdeletions was found in the group of unselected infertile Croatian men.

针对Y染色体微缺失检测两种不同方案的比较

目的:比较两种Y染色体微缺失检测方案的结果。方法:采用荧光定量PCR方法对方案一(六位点法:sY84,sY86,sY127,sY134,sY254,sY255)和方案二(八位点法:sY84,sY86,sY127,sY134,sY254,sY255,sY145,sY152)的检测结果进行比较。结果:六位点法AZF区的缺失检出率为9.34%(575/6177),八位点法AZF区的缺失检出率为8.85%(542/6122),两种方法AZF区的缺失检出率没有显著差异。结论:虽然八位点法增加对AZFd区域位点的检测,但缺失检出率与六位点法无差异。因此,从实验操作、经济成本及对临床策略指导等方面考虑,Y染色体微缺失检测六位点法优于八位点法。

Y染色体平衡易位与精液质量的相关性研究

目的分析Y染色体平衡易位与男性精液质量的相关性。方法回顾性分析2019年1月—2021年12月北京大学第三医院生殖医学中心就诊的男性病例资料,筛选出14例染色体核型分析为Y染色体平衡易位病例,以及同期185例染色体核型结果正常(46,XY)的男性作对照。通过比较两组间精液常规质量,包括精子的数量、活率以及形态学检测,分析Y染色体与常染色体间平衡易位与男性精液质量的相关性。结果除精液量外,Y染色体平衡易位患者的精液密度、精子总数、精子活率、前向运动精子百分率以及正常形态精子百分率均显著低于对照男性组。14例患者中有7例为无精子症,7例为严重少弱畸形精子症。q12(14例)、q11.23(4例)是Y染色体平衡易位断裂点高发区域。结论Y染色体平衡易位对于精子数量、活力及形态具有显著影响,严重时可导致少弱畸形精子症或无精症,影响患者的生育能力。

染色体核型分析与Y染色体微缺失联合检测无精子或少精子症的临床应用研究

目的对男性无精子或少精子症患者进行染色体遗传学病因诊断与分析,探讨染色体核型分析与Y染色体微缺失联合检测对无精子或少精子症的临床应用价值。方法收集四川泸州地区240例男性无精子或少精子症患者的临床资料及外周血样本。外周血淋巴细胞按常规染色体培养G显带行核型分析,Y染色体微缺失检测采用多重PCR技术。结果240例男性无精子或少精子症患者中无精子症患者179例、严重少精子症患者61例。单一染色体核型分析异常检出率为22.92%(55/240),包括单纯染色体数目异常30例、单纯染色体结构异常21例和合并异常4例。单一Y染色体微缺失异常检出率为10.42%(25/240),其中AZFc缺失异常率最高为7.08%。采用核型分析与Y染色体微缺失联合检测的异常检出率为30.83%(74/240),其中6例患者两项结果均异常,两种方法联合应用时较单一方法的检出率高(χ^(2)=30.24,P<0.001)。结论系统地报道了泸州地区男性无精子或少精子症患者的染色体核型及Y染色体微缺失的发生率及类型,同时提出两种方法联合应用可提高异常检出率,对男性不育症患者的病因诊断、遗传咨询及生殖治疗提供了重要指导作用。

Y chromosome microdeletion screening using a new molecular diagnostic method in 1030 Japanese males with infertility

The azoospermia factor(AZF)region is important for spermatogenesis,and deletions within these regions are a common cause of oligozoospermia and azoospermia.Although several studies have reported this cause,the present research,to the best of our knowledge,is the first large-scale study assessing this factor in Japan.In this study,1030 male patients with infertility who were examined for Y chromosome microdeletion using the polymerase chain reaction-reverse sequence-specific oligonucleotide(PCR-rSSO)method,a newly developed method for Y chromosome microdeletion screening,were included.The study enrolled 250 patients with severe oligospermia and 717 patients with azoospermia.Among the 1030 patients,4,4,10,and 52 had AZFa,AZFb,AZFb+c,and AZFc deletions,respectively.The sperm recovery rate(SRR)of microdissection testicular sperm extraction in patients with AZFc deletions was significantly higher than that in those without AZF deletions(60.0%vs 28.7%,P=0.04).In patients with gr/gr deletion,SRR was 18.7%,which was lower than that in those without gr/gr deletion,but was not statistically significant.In conclusion,our study showed that the frequency of Y chromosome microdeletion in male patients in Japan was similar to that reported in patients from other countries,and SRR was higher in patients with AZFc deletion.