中国特发性无精子症和少精子症患者雄激素受体基因CAG重复多态性研究

目的分析中国特发性无精子症和少精子症患者雄激素受体(AR)基因(CAG)n微卫星多态性并探讨该多态性与精子生成障碍发生的关系。方法应用PCR和变性聚丙烯酰胺凝胶电泳分析技术对52例少精子症患者和31例无精子症患者的外周血标本进行CAG重复数测定,分析该微卫星多态性和精子生成障碍发生的关系。结果少精子症患者组和无精子症患者组CAG重复数均数分别为22.19和22.13,CAG重复数≥28的百分率分别为1.9%和3.2%,比例逐渐升高。结论AR基因(CAG)n微卫星的CAG重复数在中国男性不育患者中呈现多态性,与精子生成障碍发生的关系有待进一步研究。     

雄激素受体基因CAG多态性对男性激素避孕有效性影响的研究

目的:分析应用肌注十一酸睾酮酯(TU)进行激素避孕的男性志愿者中起反应者与不起反应者雄激素受体(AR)基因(CAG)n微卫星多态性,并探讨该多态性对激素避孕效果的影响。方法:29例TU不起反应者和34例起反应者分别作为试验组和对照组,应用PCR和DNA测序技术对两组外周血标本进行CAG重复数测定,分析该微卫星多态性对激素避孕效果的影响。结果:试验组和对照组CAG重复数的均数分别为23.62和22.97,均数比较差异无显著性(P>0.05)。短组CAG(n≤22)在试验组和对照组的分布分别为51.7%、50.0%;长组CAG(n>22)在试验组和对照组分布分别为48.3%、50.0%,长短组分布相同。CAG重复数与精子密度之间未见相关性。在FSH浓度>0.2IU/L组中,CAG重复数>22的受试者达到无精子症的机会是其他受试者的1.5倍。结论:受试者AR基因(CAG)n重复数呈多态性,但不反应组与反应组之间不具有显著性差异,AR基因CAG重复数或其他因素与男性激素避孕效果之间的关系有待进一步探讨。     

中国生育男性DNA聚合酶γ基因CAG三核苷酸重复及与特发性男性不育的相关性研究

目的:分析中国特发性男性不育患者与正常男性DNA聚合酶γ(Polg)基因CAG三核苷酸重复,探讨CAG三核苷酸重复序列多态性与男性不育的关系。方法:应用PCR结合基因扫描(GeneScan)分型技术,对104例正常对照与55例弱精子症患者、57例少精子症患者、34例无精子症患者进行Polg基因分型。结果:弱精子症患者10/not10基因型比例大于其他各组,但统计学分析差异无显著性。结论:首次提示Polg基因CAG三核苷酸重复数目在欧洲和中国正常男性中可能存在人种差异,而10/not10基因型与精子运动障碍的关系需进一步研究。     

雄激素受体基因CAG多态性对男性激素避孕有效性影响的研究

目的：分析应用肌注十一酸睾酮酯（TU）进行激素避孕的男性志愿者中起反应者与不起反应者雄激素受体（AR）基因（CAG）n微卫星多态性，并探讨该多态性对激素避孕效果的影响。方法：29例TU不起反应者和34例起反应者分别作为试验组和对照组，应用PCR和DNA测序技术对两组外周血标本进行CAG重复数测定，分析该微卫星多态性对激素避孕效果的影响。结果：试验组和对照组CAG重复数的均数分别为23．62和22．97，均数比较差异无显著性（P〉0．05）。短组CAG（n≤22）在试验组和对照组的分布分别为51．7％、50．0％；长组CAG（n〉22）在试验组和对照组分布分别为48．3％、50．0％，长短组分布相同。CAG重复数与精子密度之间未见相关性。在FSH浓度〉0．2IU／L组中，CAG重复数〉22的受试者达到无精子症的机会是其他受试者的1．5倍。结论：受试者AR基因（CAG）n重复数呈多态性，但不反应组与反应组之间不具有显著性差异，AR基因CAG重复数或其他因素与男性激素避孕效果之间的关系有待进一步探讨。     

DAZL基因多态性位点(A260G、A386G)与无精子症和少精子症的关联性Meta分析

目的:探讨DAZL基因多态性位点(A260G,A386G)与无精子症和少精子症导致男性不育的关联性。方法:计算机检索Pub Med、Science direct、Wiley online library、中国知网、维普中文科技期刊数据库、万方数据库,查找并筛选出研究DAZL基因多态性位点A260G和A386G与男性不育关系的病例对照研究,同时查阅检索结果中所附相似文献及参考文献,检索时限均为各数据库建库至2013年11月30日。由2名评价员单独进行文献筛选及资料提取,采用Stata SE12.0软件进行Meta分析以及其他相关统计学分析。结果:共纳入文献13篇(A260G位点多态性10篇,A386G位点多态性11篇);男性不育患者共2 715例,其中少精子症或无精子症患者共2 500例,健康对照1 835例。Meta分析结果显示,DAZL A260G位点多态性在等位基因模型、显性基因模型、隐性基因模型、共显性基因模型、超显性基因模型差异无统计学意义(P0.05)。而DAZL A386G位点多态性的分析表明,亚洲人中DAZL A386G位点多态性与少精子症或无精子症在等位基因模型、显性基因模型、共显性基因模型(AA/AG)和超显性基因模型下整体效应差异有统计学意义:等位基因模型优势比(OR)=0.15,95%可信区间(CI)0.07~0.34,P0.05;显性基因模型OR=0.16,95%CI 0.07~0.35,P0.05;共显性基因模型(AA/AG)OR=0.15,95%CI0.06~0.33,P0.05;超显性基因模型OR=0.15,95%CI 0.06~0.33,P0.05。地区亚组分析结果显示,中国A386G位点多态性与少精子症或无精子症患者在等位基因模型、显性基因模型和超显性基因模型下总效应差异有统计学意义:等位基因模型OR=0.11,95%CI 0.04~0.28,P0.05;显性基因模型OR=0.11,95%CI 0.04~0.28,P0.05;共显性基因模型(AA/AG)OR=0.09,95%CI 0.03~0.26,P0.05;超显性基因模型OR=0.09,95%CI 0.03~0.26,P0.05。结论:DAZL A260G位点多态性与精子生成或精子数量下降无相关性,而DAZL A386G位点多态性与精子生成或精子数量下降有相关性,而在地区亚种分析和人种亚组分析中这种相关性只在中国存在,因此探求DAZL A260G和A386G基因多态性与无精子症或少精子症导致的男性不育之间的相关性需要更多高质量的研究。     

男性不育的遗传学病因研究进展

许多非梗阻性无精子症和严重少精子症患者的病因尚不清楚。据估计,其中约有30%的患者是由于染色体畸变或基因突变等遗传学因素引起的。男性不育的遗传学病因有染色体畸变、Y染色体微缺失和基因突变等,其中Klinefelter综合征和Y染色体微缺失最为常见。与男性不育相关的基因突变包括囊性纤维化跨膜介导的调节子(CFTR)基因、雄激素受体(AR)基因、胰岛素样因子3(INSL3)基因和富含亮氨酸重复序列的G蛋白偶联受体8(LGR8)基因。CFTR基因突变可导致囊性纤维化、输精管缺如和梗阻性无精子症。AR基因突变会引起雄激素不敏感综合征和生精损伤。INSL3和LGR8基因突变则与睾丸下降异常和隐睾相关。Meta分析显示,仅有3个遗传多态性与男性不育显著相关,即AZFc区部分缺失、雄激素受体(AR)基因(CAG)n长度和亚甲基四氢叶酸还原酶(MTHFR)基因多态性。本文主要综述了男性不育常见的遗传学病因以及与男性不育相关的遗传多态性研究进展。     

超氧化物歧化酶2基因rs4880位点单核苷酸多态性与男性不育发病风险的相关性研究

目的:探讨超氧化物歧化酶2(SOD2)基因rs4880位点单核苷酸多态性与男性不育发病风险的相关性。方法:采用病例-对照研究的方法,选取519例特发性男性不育患者作为病例组,年龄19~40(28.92±4.37)岁,并按精子浓度和前向运动(PR)精子百分率分为无精子症组(n=143)、严重少精子症组(n=175)、少精子症组(n=89)和弱精子症组(n=112)4个亚组;以338例正常生育的男性作为对照组,年龄19~40(28.40±4.25)岁,进行临床数据的采集。用Sequenom Mass Array技术对SOD2 rs4880位点进行基因分型,用Logistic回归模型分析SOD2 rs4880位点不同基因型与男性不育之间的关系。结果:病例组与正常对照组FSH、PR精子百分率、精子浓度存在显著差异(P0.01)。与野生型纯合TT比较,杂合突变型TC(OR=0.90,95%CI:0.65~1.25,P=0.516)与纯合突变型CC(OR=1.49,95%CI:0.38~5.81,P=0.566)均显示与男性不育无相关性;亚组分析中均显示该基因位点与男性不育不存在相关性:无精子症组中,TC/TT(OR=0.99.95%CI:0.62~1.58,P=0.967),CC/TT(OR=1.58,95%CI:0.26~9.59,P=0.619;严重少精子症组中,TC/TT(OR=1.07.95%CI:0.70~1.64,P=0.750),CC/TT(OR=1.31,95%CI:0.22~7.96,P=0.767;少精子症组中,TC/TT(OR=0.83.95%CI:0.47~1.48,P=0.535),CC/TT(OR=1.22,95%CI:0.13~11.90,P=0.865);弱精子症组中,TC/TT(OR=0.59.95%CI:0.33~1.05,P=0.074),CC/TT(OR=1.84,95%CI:0.30~11.16,P=0.510)。结论:SOD2 rs4880位点基因多态性与男性不育不存在相关性,但是由于实验样本条件的限制,需要更大的样本量以及样本选取范围来进一步研究验证。     

前列腺癌与雄激素受体基因(CAG)n重复多态性的关系

目的　探讨前列腺癌 (PC)与雄激素受体 (AR)基因 (CAG)n重复多态性的关系。　方法　应用DNA双链循环测序方法对 34例PC组织与癌旁正常组织、2例PC患者外周血白细胞内的AR基因 (CAG)n重复数进行测定。　结果　同一PC患者的癌组织与癌旁正常组织 (CAG)n重复数相同 ;36例患者癌组织AR基因 (CAG)n呈重复多态性 ,平均 2 0 .0 6 ,显著低于正常组织 ,差别有显著性意义 (P <0 .0 5 ) ;不同分化程度的癌组织 (CAG)n重复数差别无显著性意义 (P >0 .0 5 )。　结论　AR基因 (CAG)n重复数改变的体细胞突变在PC癌细胞中罕见 ,该重复数的减少可能与PC发病相关     

雄激素受体基因CAG多态性与迟发性性腺功能减退症的相关性研究

目的:研究雄激素受体基因(AR)重复序列(CAG)n多态性与迟发性性腺功能减退症(LOH)的关系,探讨LOH的发病机制。方法:共调查1 000例40～70岁中老年男性,其中19例迟发性性腺功能减退症患者,随机抽取127例正常健康中老年男性,测定甘油三酯(TG)、空腹血糖(FBG)、血清总睾酮(TT)、游离睾酮(fT),测量身高、体重、腰围(WC)、血压,并采用DNA测序方法进行AR基因外显子1氨基端转录调节区(CAG)n重复序列长度测定,比较两组各指标之间的差异。结果:(CAG)n重复次数为15～32(23.05±2.95)。正常健康中老年男性的体重指数(BMI)、FBG较LOH患者显著下降(P<0.01),而TG、TT及fT较LOH患者显著升高(P<0.01)。正常健康中老年男性AR基因(CAG)n重复数为22.54±3.06;LOH患者AR基因(CAG)n重复数为23.23±2.24;LOH患者(CAG)n重复数略高于正常健康人群,但两者比较无统计学意义(P=0.946)。(CAG)n重复长度显示:长组(n≥22)AR基因(CAG)n在LOH组和正常健康中老年男性组的频率分别为73.68%和48.82%(P<0.05)。相关分析显示:TT、fT与(CAG)n重复序列无明显相关性(r=0.04和r=0.025,P>0.05)。结论:LOH男性AR基因(CAG)n重复序列呈现多态性,长(CAG)n重复多态可能是LOH发病的遗传因素,但仍需进一步扩大样本量证实。     

雄激素受体CAG重复多态性与BPH和PCa相关性的meta分析

目的:通过meta分析探讨雄激素受体(AR)基因CAG重复多态性与良性前列腺增生(BPH)和前列腺癌(PCa)发病风险的关系。方法:检索国内外大型数据库发表的AR基因CAG重复多态性与BPH和PCa相关性的文献,基于异质性检验的结果,分别采用M-H固定效应模型和随机效应模型合并比值比(OR)效应量,采用Begg和Egger偏倚分析评估本项meta分析的发表偏倚,系统评价AR基因CAG重复多态性与BPH和PCa发病风险的关系,并按种族进行分层分析。结果:检索获得文献29篇,最终纳入4篇符合条件的文献,累计BPH患者485例、PCa患者767例、正常对照组709例。BPH组和正常对照组间不存在异质性,M-H固定效应模型合并效应量后提示低CAG重复多态性与BPH无相关性。PCa组和BPH组及对照组间均存在异质性,随机效应模型提示低CAG重复多态性与PCa的风险呈正相关(OR PCa/对照=1.45,OR PCa/BPH=1.86,OR PCa/(BPH+对照)=1.66)。种族分层的亚组分析提示,低CAG重复多态性与PCa发病风险在种族间存在差异。Begg和Egger偏倚分析显示各组比较中均无显著发表偏倚。结论:AR受体低CAG重复多态性与PCa发病风险呈正相关,与BPH发病风险无相关性。     

CAG repeat expansion in the androgen receptor gene is not associated with male infertility in Indian populations

CAG repeat expansion in exon 1 of the androgen receptor (AR) gene has been reported to be associated with male infertility in some but not all populations. Until now, studies have not been carried out to examine this among Indian populations. For the first time, we have analyzed the CAG repeat motif in the AR gene in 280 men with azoospermia and in 201 men with normal fertility. The mean number of CAG repeats in the AR gene of men with azoospermia was 21.7 +/- 0.18, with a high incidence of repeat number 22. Among fertile-control men, the mean number of CAG repeats was 22.4 +/- 0.19, with a predominance of repeat number 23. The highest number of CAG repeats (32) was found with low frequency in both fertile and azoospermic groups. Comparison of fertile men and those with azoospermia on the basis of CAG repeats revealed that the number of CAG repeats in both groups were similar, as revealed with a paired t test (t = 0.04; P =.967). Expansion of the CAG repeat in the AR gene is therefore not associated with male infertility in Indian populations. This suggests that what is true for one population may not be true for other populations.     

Association of oestrogen receptor alpha polymorphisms and androgen receptor CAG trinucleotide repeats with male infertility: a study in 109 Greek infertile men

This study was performed to examine the contribution of genetic polymorphism of oestrogen and androgen receptor (AR) genes in male infertility. We have studied in total 173 Greek men, 109 infertile patients and 64 controls (group A). Patients were divided in to three subgroups: group B (n=29) with idiopathic moderate oligospermia, group C (n=42) with azoospermia or idiopathic severe oligospermia and group D (n=38) with azoospermia or oligospermia of various known aetiologies. All patients and controls were genotyped for two polymorphisms of the oestrogen receptor alpha (ERalpha) gene and also for the (CAG)n repeat length polymorphism of the X-linked androgen receptor (AR)gene. The control group had statistically significant difference from group C regarding the XbaI polymorphism of ERalpha gene. Despite the fact that we did not observe any statistically significant differences in the mean and range of the CAG repeat number, the frequency of the higher repeats of the nucleotide repeat sequence (CAG)n of the AR gene was 2-4 times higher in groups B and C compared with the control group A. Our results indicate that both ERalpha and AR gene play significant role in male fertility. It is possible that a synergy may exist between unfavourable genotypes of these two genes in male infertility.     

Androgen receptor gene haplotype is associated with male infertility

The purpose of the current study was to evaluate the importance of androgen receptor ( AR ) gene haplotypes and polymorphic CAG/GGN microsatellites in the aetiology of male infertility. We genotyped six haplotype-tagging single nucleotide polymorphisms and CAG/GGN microsatellites of the AR gene in 112 infertile and 212 control Estonian men. A total of 13 AR haplotypes (HAP1–13) were identified, among which HAP4 was found to confer increased risk for male infertility (OR = 5.15, 95% CI = 1.75–15.15, p  = 0.003). However, infertile patients and controls had similar lengths and distributions of both AR CAG (mean ± SD number of repeats 21.1 ± 2.5 vs . 21.2 ± 2.3, respectively) and GGN (mean ± SD number of repeats 22.5 ± 1.5 vs . 22.4 ± 1.9, respectively) repeats. In addition, HAP2 was associated with more CAG repeats ( r  = 1.17, p  = 0.033) and HAP3 with fewer CAG repeats ( r  = −2.93, p  < 0.001) than the major haplotype HAP1. HAP3 and HAP4 were associated with more GGN repeats ( r  = 1.35, p  = 0.001 and r  = 1.36, p  = 0.002, respectively) than HAP1. In conclusion, our results implicated the AR -HAP4 gene haplotype in increased risk for male infertility, while no association was found between AR CAG/GGN microsatellites and impaired spermatogenesis.     

CAG repeat length in androgen receptor gene and male infertility in Egyptian patients

The CAG repeat and its association with infertility has been debatable. Therefore, this study was planned to assess the distribution of CAG repeat expansion in Egyptian patients and to investigate its association with male infertility. Forty-five infertile men were eligible for the study in addition to 20 aged-matched fertile males as control. Semen analysis, scrotal sonography, assay of serum testosterone, follicle-stimulating hormone (FSH) and luteinising hormone (LH), and determination of the CAG repeat number within exon 1 of the androgen receptor (AR) gene were carried out. Statistically significant difference was found between infertile and control groups regarding sperm count, sperm motility, serum FSH level and CAG repeats (P < 0.05); statistically insignificant difference for the CAG repeats (P = 1.0) was found between oligozoospermic and asthenospermic groups; negative correlation was found between CAG repeat length and sperm count, and a positive correlation was found between CAG repeat length and serum FSH (P < 0.05). Our results validate the concept that long stretches of CAG repeat may be associated with lower AR function with derangement of sperm production, and this may contribute to male infertility in Egyptian men.     

The contributions of deficient androgen action in spermatogenic disorders

The contributions of deficient androgen actions in spermatogenic disorders causing idiopathic male infertility are reviewed. The physiological role of androgens in spermatogenesis, the mechanism of actions of testosterone and the clinical implication of androgen deficiency are explained. The role of mutations in the androgen receptor (AR) in idiopathic infertility and, in particular, the contribution of expanded cytosine-adenine-guanine (CAG) repeats in exon 1 of the AR gene to the occurrence of male idiopathic infertility is highlighted. Possible future aspects of treatment for such patients are discussed.     

No association of androgen receptor GGN repeat length polymorphism with infertility in Indian men

Androgens, acting through the androgen receptor (AR), play a role in secondary sexual differentiation from the prenatal stage to adulthood, including spermatogenesis. The AR gene has 2 polymorphic trinucleotide repeats (CAG and GGN) in exon 1. The CAG repeat length polymorphism has been well studied in a variety of medical conditions, including male infertility. Many of these studies have shown an association of the expanded CAG repeats with male infertility, although this is not true for all populations. The GGN repeat, in contrast, has been less thoroughly studied. Thus far, only 4 reports worldwide have analyzed the GGN repeat, alone or in combination with the CAG repeat, in male infertility cases. No such study has been undertaken on infertile Indian men. Therefore, we have analyzed AR-GGN repeats in a total of 595 Indian males, including 277 azoospemric, 97 oligozoospermic, and 21 oligoteratozoospermic cases, along with 200 normozoospermic controls. The analysis revealed no difference in the mean number or the range of the repeat between cases (mean = 21.51 repeats, range 15-26 repeats) and controls (mean 21.58 repeats, range 15-26 repeats). Furthermore, no difference was observed when azoospermic (mean = 21.53 repeats, range 15-26 repeats), oligozoospermic (mean = 21.46 repeats, range 15-26 repeats), and oligoteratozoospermic cases (mean = 21.48, range 19-26 repeats) were compared individually with the controls.     

The association of androgen- and oestrogen-receptor gene polymorphisms with urolithiasis in men

OBJECTIVE: To evaluate the association of urolithiasis with polymorphic microsatellite (encoding cytosine, adenine, and guanine, CAG) repeats in the exon 1 region of the androgen receptor (AR) gene and thymine/adenine (TA) repeats in the oestrogen receptor (ER). PATIENTS AND METHODS: Patients with urolithiasis (149) and a group of normal controls (102) were examined and compared. The CAG repeats of the AR gene and TA repeats of the ER gene were detected by polymerase chain reaction. The CAG repeats ranged from 171 bp (10 CAG repeats with 141 bp of amplified flanking sequences) to 270 bp (43 CAG repeats). The TA repeats ranged from 160 bp to 194 bp. Associations between calcium oxalate stone disease and the CAG repeats in AR gene and TA repeats in ER gene were then evaluated. The results were classified according to sex and peaks in allelic frequency distribution. RESULTS: There was a significant difference between the male stone patients and the normal controls in the distribution of CAG repeats in the AR gene. Both groups showed a high percentage of 21-repeats in the allelic distribution, at 17 (16%) and 20 (37%) in stone patients and normal controls, respectively. The results indicate that 21-CAG repeats might be related to a lower risk of stone formation in men (P < 0.05). In the ER gene, the peak allelic distribution of TA repeats was 14, showing a significant difference between male stone patients and the normal control subjects (P < 0.01). There were no statistical differences between female stone patients and the control subjects in either the AR or the ER gene. CONCLUSION: Urolithiasis among men appears to be associated with AR gene CAG repeat and ER gene TA repeat polymorphisms, whereas there was no significant association among female stone patients. These sex hormone receptors seem to be related to the higher incidence of stone formation among men.     

Cytogenetic and molecular analysis of the Y chromosome: absence of a significant relationship between CAG repeat length in exon 1 of the androgen receptor gene and infertility in Indian men

The genetic basis of male infertility remains unclear in the majority of cases. Recent studies have indicated an association between microdeletions of the azoospermia factor a (AZFa)-AZFc regions of Yq and severe oligospermia or azoospermia. Increased (CAG)n repeat lengths in the androgen receptor (AR) gene have also been reported in infertile men. Therefore, in order to assess the prevalence of these genetic defects to male infertility, 183 men with non-obstructive azoospermia (n = 70), obstructive azoospermia (n = 33), severe oligospermia (n = 80) and 59 fertile men were examined cytogenetically and at molecular level for Yq deletions, microdeletions, and AR-CAG repeat lengths along with hormonal profiles [luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone (T)]. We used high resolution cytogenetics to detect chromosome deletions and multiplex polymerase chain reaction (PCR) involving 27 sequence-tagged site (STS) markers on Yq to determine the rate and extent of Yq microdeletions. PCR amplification with primers flanking exon 1 of AR gene was used to determine the AR-(CAG)n repeat lengths. Hormonal profiles (LH, FSH and T levels) were also analysed in infertile and fertile men. Testicular biopsies showed Sertoli cell only (SCO) morphology, maturation arrests (MA) and hypospermatogenesis. No chromosome aberrations were found in infertile men but there was a significant increase (p < 0.001) in the association of acrocentric chromosomes including the Y chromosome. Yq microdeletions were found in 16 non-obstructive azoospermic men (16 of 70; 22%) and seven severe oligospermic individuals (seven of 80; 8.7%) and most of them had deletions in the sY240 locus. No Yq microdeletions were detected in patients with obstructive azoospermia. No statistically significant difference in the mean length of CAG repeats in AR gene was observed between infertile and fertile men (22.2 +/- 1.5 and 21.5 +/- 1.4 respectively). No significant increase or decrease in levels of LH, FSH and T was observed in infertile and fertile men. In some infertile men, significantly elevated levels of FSH alone or in combination with LH were found to be indicative of failure of spermatogenesis and/or suggestive of testicular failure. Y-chromosome microdeletions contribute to infertility in some patients but no relationship could be established with the (CAG)n repeat lengths in exon 1 of the AR gene in infertile Indian men.