AZF基因微缺失与男性不育研究进展

由于基因缺陷所引起的生精障碍是导致男性不育的重要原因之一。其中,Y染色体无精症因子（azoospermia factor,AZF）区域微缺失与男性不育密切相关,是最常见的导致无精症与严重少精症的分子遗传病因。本文旨对AZF基因微缺失与男性不育研究进展作一综述。     

特发性无精症和严重少精症患者Y染色体无精子因子的微缺失检测

生精障碍是男性不育的主要原因。研究发现，位于Y染色体长臂上存在着被称为无精子因子(azoospermia factor，AZF)的基因，它的DNA微缺失可以导致男性生精障碍所致的男性不育症。本文报道采用PCR方法对65例特发性无精症或严重少精症患者进行Y染色体的AZF基因微缺失的检测结果。     

男性不育患者Y染色体微缺失筛查方法的建立和初步应用

目的 建立一套Y染色体微缺失的多重PCR筛查方法，对无精症或少精症男性不育患者进行Y染色体微缺失的常规筛查。方法 建立5套稳定和可靠的多重PCR筛查方法，对进行单精子卵细胞浆注射治疗的87例无精症和少精症患者及进行睾丸活检的30例无精症患者做Y染色体微缺失的检测。结果 共有19例发现微缺失(16．2％)，其中61例少精症患者中发现11例(18．0％)，56例无精症患者中发现8例(14．3％)。结论 Y染色体微缺失的多重PCR筛查方法是易行和可靠的，对无精症和少精症患者有必要进行Y染色体微缺失的常规筛查。     

广州地区不育男性Y染色体无精子因子微缺失的筛查

目的探讨Y染色体无精子因子(azoospermia factor,AZF)区域微缺失与原发无精、严重少精症之间的关系。方法采用多重聚合酶链反应技术对广州地区103例原发无精子症、72例原发严重少精症患者及60名正常生育男性进行AZFa、AZFb、AZFc3个区域微缺失分析。结果60名正常生育男性未发现Y染色体AZF区域微缺失,175例生精障碍患者中发现AZF微缺失19例,总缺失率为10.9%。其中11例无精症患者和4例少精症患者的缺失发生在AZFc区域,缺失率为8.6%;1例无精症患者和2例少精症患者发生AZFb、AZFc双重缺失,缺失率为1.7%;1例无精症患者发生AZFa、b、c3个区域同时微缺失,缺失率0.6%。生精障碍组与正常生育男性组比较Y染色体AZF区域微缺失率差异具有统计学意义(P<0.01)。结论Y染色体AZF区域微缺失是引起男性无精、少精子症的重要原因之一,对原发无精、少精子症患者在单精子注射之前进行微缺失筛查是必要的。     

112例生精障碍患者细胞遗传学分析

生精功能障碍是男性不育的一个重要原因,约占男性不育的10%,它表现为无精子症和严重的少精子症.本文对自1991年至2002年112例生精障碍患者进行细胞遗传学分析,现报告如下.     

不明原因无精症及少精症的AZF微缺失的分析

目的 探讨男性不育患者中无精症、少精症与Y染色体基因(无精子因子,AZF)微缺失的关系,建立一个完整的适合中国人的AZF微缺失筛查的临床基因诊断方法.方法 对62例无精症、少精症患者及20例正常男性采用多重聚合酶链反应法进行AZF区基因微缺失检测.结果 44例无精症患者中存在6例缺失,占13.64%,18例少精症患者中存在4例缺失,占22.22%,缺失以AZFc区为主,20例正常男性对照AZF无缺失.结论 Y染色体AZF微缺失是不明原因无精症、少精症的主要原因之一.     

特发性无精症与严重少精症患者DAZ基因缺失的研究

目的：探讨无精子缺失（deleted in azoospermia，DAZ）基因与精子发生的关系，以及特发性无精症与严重少精症患者DAZ基因缺失的发生率。方法：应用聚合酶链反应对特发性无精症或严重少精症患者DAZ基因进行检测，并结合患者的生殖激素水平及临床表型进行分析。结果：38例特发性无精症或严重少精症患者中有3例DAZ基因缺失，缺失率为7.9%，3名患者的血清FSH水平均升高。20名精子计数正常、有生育能力的男性无DAZ基因缺失。结论：DAZ基因可能与精子发生相关，DAZ的微缺失可能是造成男性不育的原因之一。     

Y染色体AZF基因微缺失和男性不育的相关性研究进展

男性不育的主要临床症状是无精子症和少精子症。引起男性不育的因素很多,其中由于遗传因素所导致的生精障碍是引起男性不育的重要原因之一。研究发现,Y染色体长臂上无精子因子（azoospermia factor,AZF）的缺失可以导致男性生精障碍,大多表现为无精子或严重少精子,与男性不育密切相关,并且可以正常生育或辅助生育方式遗传给后代引起不育。进行AZF基因微缺失的检测可以为患者的诊断、治疗及遗传咨询提供理论依据并减少不必要的治疗。     

67例不育男性血清性激素的检测分析

男性不育是临床常见病之一,病因较复杂。本院从1994年8月～1995年4月对来院诊治的67例无精或少精者(<10M/ml)进行了血清放射免疫FSH、LH、PRL、T的测定,现将结果报告如下。 对象和方法 一、对象:选自来院诊治的男性不育症患者。通过精液常规检测确诊为无精症或少精症(<10M/ml)者。     

494例生精障碍患者的染色体核型分析

目的通过对生精障碍患者外周血染色体核型的分析,探讨染色体核型异常与男性不育的关系。方法常规制作外周血染色体G显带,对494例生精障碍患者进行染色体核型分析。结果在494例生精障碍患者中,共检出染色体异常30例,发生率为6.07%(30/494),其中无精症、严重少精症和少精症患者的发生率分别为11.86%(21/177)、3.39%(6/177)、2.08%(3/144)。在异常染色体核型中,有13例(13/30,43.33%)发生染色体数目异常,17例(17/30,56.67%)发生染色体结构异常,其中14例(14/30,46.67%)是性染色体异常,16例(16/30,53.33%)是常染色体异常。在所有核型中,Klinefelter综合征的发生率最高,占异常核型的43.33%。结论生精障碍功能越严重,染色体异常核型检出率越高。因此有必要对生精障碍的患者进行染色体核型分析,从而帮患者找出病因,明确诊断,为进行辅助生育的不育患者提供遗传咨询,避免将缺陷传给后代。     

Quantification by magnetic resonance spectroscopy of metabolites in seminal plasma able to differentiate different forms of azoospermia

The aim was to determine whether proton magnetic resonance spectroscopy (1H-MRS) of metabolites such as glycerophosphorylcholine (GPC), choline, citrate and lactate in human seminal plasma can be used to differentiate (i) different azoospermic patients and (ii) different forms of spermatogenic failure including those who had undergone radiation therapy or chemotherapy. Semen samples were provided by men with obstructive azoospermia and spermatogenic failure who had serum follicle stimulating hormone (FSH) values within the normal range and either more or less than normal. Four prominent constituents of seminal plasma were identified by 1H-MRS: GPC, choline, citrate and lactate. The peak area ratios of choline/citrate as well as choline/lactate were significantly different (P < 0.01) between groups with spermatogenic failure and obstructive azoospermia. When the serum FSH values were normal in men with spermatogenic failure and obstructive azoospermia, a significant difference was found in the GPC/choline ratio (P < 0.001). When the FSH values were normal, the GPC/choline ratio appeared to be a very important parameter able to differentiate not only between cases of spermatogenic failure and obstructive azoospermia but also between different forms of spermatogenic failure. These results demonstrate the potential use of 1H-MRS on human seminal plasma in a new approach in the management of male infertility.      

Associations of Y-chromosome subdeletion gr/gr with the prevalence of Y-chromosome haplogroups in infertile patients

Microdeletions in azoospermia factor (AZF) region on distal Yq are associated with male infertility and spermatogenic failure due to intra-chromosomal homologous recombination between large nearly identical repeat amplicons and are found in ∼10% of azoospermic and severe oligozoospermic cases. Although AZFc is deleted in azoospermia or oligozoospermia, no definitive conclusion has been drawn for the role of partial AZFc deletions to spermatogenic failure. Therefore, this study is planned to investigate the role of gr/gr subdeletions in individuals with spermatogenic failure and to find its relationship with Y chromosome haplogroups (HGs) in infertile men from Indian population. It is a case-control study involving 236 azoospermic, 182 oligospermic and 240 healthy normozoospermic men. We found 18 gr/gr, 11 b1/b3 and 2 b2/b3 subdeletions in azoospermic patients and 12 gr/gr, 5 b1/b3 and 4 b2/b3 subdeletions in oligospermic patients. However, we also found seven gr/gr deletions in normozoospermic men. Seven patients each with spermatogenic arrest and oligospermia who carry gr/gr subdeletions have deleted DAZ3/DAZ4 genes. A total of 11 patients with sertoli cell-only syndrome (SCOS) and 5 oligospermic patients with gr/gr subdeletions also have DAZ1/DAZ2 genes deleted indicating that deletions of DAZ genes contributed differently to damage to spermatogenic process. L1 HG is found in patients showing b1/b3 subdeletions, whereas HG H1a2 and H1b were found in normozoospermic individuals with gr/gr subdeletions. Our results provide evidence of association between the occurrence of subdeletions and male infertility as well as the severity of the spermatogenic failure.     

直接低渗法制备男性不育症精液生精细胞染色体观察

目的：研究男性不育症生殖细胞减数分裂过程、生精细胞染色体畸变与不育的关系。方法：选择不育门诊中１９例男性原发不肓患者精液和４例禁欲期正常男性志愿者精液，应用直接低渗法，获得各级生精细胞（精原细胞、初级／次级精母细胞、精细胞）分裂相。结果：不同样本精液中各级生精细胞分裂相分布有极显著性差异（Ｐ〈０．００５）；弱精症患者精液标本中主要为ＭＩ单价体、染色单体畸变，少精症和无精症主要为联会消失、减数分裂阻断。结论：直接低渗法能为诊断男性不育提供有价值的细胞遗传学信息。生精细胞染色体畸变、减数分裂过程异常是导致男性不肓的原因之一。     

精子发生障碍患者Y染色体微缺失的研究

目的研究无精子症和少精子症患者Y染色体上无精子症因子(azoospermicfactor,AZF)微缺失情况,建立Y染色体微缺失的分子诊断的临床筛查方法,分析原发性无精子症和少精子症患者与Y染色体微缺失的关系。方法采用多重PCR、凝胶电泳技术对56例无精子症和少精子症患者的10个STS位点或基因进行检测与筛查。结果20例精子密度正常的生育男性未检测出Y染色体微缺失;56例无精子症和少精子症患者中有9例有AZF区域的微缺失,总缺失率16.1%(9/56),AZFc/DAZ区发生微缺失频率较高。结论Y染色体微缺失是导致男性不育患者精子发生障碍的重要原因之一,AZF侯选基因在精子发生过程中可能起重要作用。     

Association of partial AZFc region deletions with spermatogenic impairment and male infertility

Background: Complete deletions of the AZFc region in distal Yq are the most frequent molecular genetic cause of severe male infertility. They are caused by intrachromosomal homologous recombination between amplicons—large, nearly identical repeats—and are found in 5–10% of cases of azoospermia and severe oligozoospermia. Homologous recombination may also generate different partial deletions of AZFc, but their contribution to spermatogenic impairment has not been confirmed.

Methods: In this study we analysed the prevalence and characteristics of different partial AZFc deletions and their association with spermatogenic failure. We studied 337 infertile men with different spermatogenic impairment and 263 normozoospermic fertile men using AZFc specific sequence tagged site markers and DAZ specific single nucleotide variants.

Results: We identified 18 cases of partial AZFc deletions in the infertile group (5.3%) and one case in the control group (0.4%). Seventeen deletions had the "gr/gr" pattern, one the "b2/b3" pattern, and one represented a novel deletion with breakpoints in b3 and b4 amplicons. Partial AZFc deletions were associated with different spermatogenic phenotypes ranging from complete azoospermia to only moderate oligozoospermia.

Conclusions: Together with published data, our analysis of DAZ gene copy suggested that the contribution of the different deletions to male infertility varies: only partial AZFc deletions removing DAZ1/DAZ2 seem to be associated with spermatogenic impairment, whereas those removing DAZ3/DAZ4 may have no or little effect on fertility. These data show that, beside complete AZFc deletions, specific partial deletions represent a risk factor for male infertility, even if with different effect on spermatogenesis.

     

常染色体异常与男性不育的细胞遗传学分析

目的探讨男性不育与常染色体异常的关系.方法 509例男性不育患者行外周血淋巴细胞G显带染色体核型分析.结果在454例特发性生精异常患者中有23(5.1%)例涉及常染色体结构异常,40(8.8%)例涉及染色体多态性.结论常染色体异常可以引起男性生精障碍.     

Y染色体与常染色体易位的遗传学分析及文献学习

目的探讨Y染色体与常染色体易位所产生的遗传效应,为男性不育遗传咨询及治疗提供依据方法回顾性分析8400例不孕不育患者,其中14例为Y染色体与常染色体易位,同时进行Y染色体微缺失检测,并辅以文献学习结果14例Y-常染色体易位中9例为46,XX／46,XY,der（15）t（Y;15）占Y-常染色体易位的64．3％,其余为Y-非近端着丝粒染色体易位,未发现合并Y染色体微缺失。结论1．Yq12与近端着丝粒染色体短臂易位,通常不引起表型和生育问题。2．Y染色体与非近端着丝粒染色体易位,会导致减数分裂异常,造成严重的生精障碍,产生无精子症和严重少弱精,从而引起男性不育。     

AZFc区gr/gr及DAZ基因拷贝缺失与原发性男性生精障碍的相关性研究

目的探讨Y染色体AZFc区gr/gr缺失及DAZ基因拷贝缺失与男性生精障碍的相关性。方法运用PCR与PCR-RFLP检测技术,对252例正常生精男性,430例原发性生精障碍男性患者进行Y染色体AZFc区gr/gr缺失及DAZ基因拷贝缺失分析。结果正常生精男性组gr/gr缺失率为5.2%,原发性生精障碍组gr/gr缺失率为10.2%,P=0.021,差异有统计学意义;正常生精男性组DAZ1/DAZ2基因拷贝共缺失率为2.0%,原发性生精障碍组中DAZ1/DAZ2基因拷贝共缺失率为7.0%,P=0.004,差异亦有统计学意义;正常生精男性组DAZ3/DAZ4基因拷贝共缺失率为3.2%,在生精障碍组中DAZ3/DAZ4基因拷贝的共缺失率为3.3%,P=0.954,差异无统计学意义。结论在原发性男性生精障碍患者中存在较高频率的gr/gr缺失及DAZ1/DAZ2基因共缺失,提示gr/gr缺失及DAZ1/DAZ2基因拷贝的共缺失是男性不育的高风险因子。     

Single nucleotide polymorphisms of the gonadotrophin-regulated testicular helicase (GRTH) gene may be associated with the human spermatogenesis impairment

BACKGROUND: Gonadotropin-regulated testicular RNA helicase (GRTH) is a testis-specific RNA helicase that is essential for completion of spermatogenesis and is involved in pathogenesis of impaired spermatogenesis in mouse. It is therefore reasonable to postulate that human GRTH gene may also play a role in impaired spermatogenesis in humans. To test this hypothesis, we investigated the possible association between the variations of the GRTH gene and human spermatogenesis impairment. METHODS: Mutation screening of exons and intron/exon boundaries of GRTH gene was carried out by denaturing high-performance liquid chromatography (DHPLC) in 347 infertile patients with idiopathic azoospermia and severe oligozoospermia as well as 201 fertile men. RESULTS: Four single nucleotide polymorphisms (SNP), namely IVS6+55G-->T, ISV8+10A-->C, c.852C-->T and c.927G-->A, were identified. Among them, significant differences in polymorphism frequencies were observed at the polymorphic IVS6+55G-->T and c.852C-->T loci between the patients and controls, and a significant association between haplotypes of these two loci and male infertility with impaired spermatogenesis was detected. CONCLUSIONS: Results of the present study indicate that SNP IVS6+55G-->T and c.852C-->T of GRTH gene may be associated with male infertility with azoospermia or severe oligozoospermia, suggesting that variations in GRTH gene may contribute to susceptibility to spermatogenic impairment in humans.