CFTR基因与先天性双侧输精管缺如关系研究进展

囊性纤维化病是囊性纤维化跨膜转运调节物(CFTR)基因突变导致的一种常染色体隐性遗传病.先天性双侧输精管缺如患者大部分有CFTR基因突变,辅助生殖技术包括卵泡浆内单精子注射技术使先天性双侧输精管缺如所致无精子症患者有生育后代的机会,但可将突变的基因遗传给下一代从而增加后代发生囊性纤维化和先天性双侧输精管缺如的危险性.CFTR基因的突变和变异特点具有人种和地域差异性,因此研究不同人种和地域人群的CFTR基因突变和多态性及其与先天性双侧输精管缺如发生相关的突变位点,有利于疾病诊断,评估卵泡浆内单精子注射术的遗传学风险.     

FTR基因与先天性双侧输精管缺如关系研究进展

囊性纤维化病是囊性纤维化跨膜转运调节物 (CFTR)基因突变导致的一种常染色体隐性遗传病。先天性双侧输精管缺如患者大部分有CFTR基因突变 ,辅助生殖技术包括卵泡浆内单精子注射技术使先天性双侧输精管缺如所致无精子症患者有生育后代的机会 ,但可将突变的基因遗传给下一代从而增加后代发生囊性纤维化和先天性双侧输精管缺如的危险性。CFTR基因的突变和变异特点具有人种和地域差异性 ,因此研究不同人种和地域人群的CFTR基因突变和多态性及其与先天性双侧输精管缺如发生相关的突变位点 ,有利于疾病诊断 ,评估卵泡浆内单精子注射术的遗传学风险     

CFTR基因与先天性双侧输精管缺如关系研究进展

囊性纤维化病是囊性纤维化跨膜转运调节物(CFIR)基因突变导致的一种常染色体隐性遗传病。先天性双侧输精管缺如患者大部分有CFTR基因突变，辅助生殖技术包括卵泡浆内单精子注射技术使先天性双侧输精管缺如所致无精子症患者有生育后代的机会，但可将突变的基因遗传给下一代从而增加后代发生囊性纤维化和先天性双侧输精管缺如的危险性。CFTR基因的突变和变异特点具有人种和地域差异性，因此研究不同人种和地域人群的CFTR基因突变和多态性及其与先天性双侧输精管缺如发生相关的突变位点，有利于疾病诊断，评估卵泡浆内单精子注射术的遗传学风险。     

男性生殖遗传学的临床研究进展

男性生殖遗传学异常包括染色体、基因、精子DNA完整性及表观遗传学等多个方面,是导致男性不育的重要病因。随着基因测序技术的进步和辅助生殖技术的广泛应用,男性生殖遗传学已成为近年来的研究热点。本文对近年的男性生殖遗传学临床研究进行了分析和总结。重点探讨了3种常见的男性生殖遗传学疾病:克氏综合征、Y染色体微缺失和先天性输精管缺如。克氏综合征的流行病学现状、临床表现、治疗方法、手术取精成功率等;Y染色体微缺失的流行病学现状、各种分型的临床表现和治疗方法,重点探讨了Y染色体AZFc区缺失的不同治疗方式及妊娠结局;先天性输精管缺如患者的CFTR基因突变情况,及其对生育的影响及治疗策略。指出了目前研究的不足,展望了未来研究的方向。     

中国男性不育的重要遗传病因:染色体异常与Y染色体AZFc区DAZ基因拷贝缺失

目的:探讨染色体的结构与数目异常,以及位于Y染色体无精子症因子C区(azoospermiafactorC,AZFc)中无精子症缺失基因家族(deleted-in-azoospermia,DAZ)基因拷贝缺失与男性不育的关系。方法:运用染色体G显带、多重PCR与PCR-RFLP检测技术,对210例已生育男性、247例无精子症与206例严重少精子症患者Y染色体AZF区结构进行分析,并对453例患者进行外周血染色体检查。结果:在无精子症与严重少精子症患者中染色体数目与结构异常发生率分别为12.6%与8.3%。所有已生育男性中未检出DAZ基因全部或部分拷贝缺失,而在无精子症与严重少精子症患者中4个DAZ基因拷贝缺失率分别为7.7%和11.2%,DAZ1/DAZ2共缺失率分别为7.3%和4.9%。结论:在中国男性无精子症与严重少精子症患者中存在较高频率的染色体结构/数目异常与DAZ基因拷贝缺失现象,提示染色体结构/数目异常与Y染色体AZFc区DAZ基因拷贝缺失可能是中国男性不育的重要遗传病因。     

山东地区男性不育与CFTR基因M470V多态性的关系

目的研究山东地区男性不育症患者和正常男性中的囊性纤维化跨膜转导调节因子(CFTR)基因M470V多态性分布情况,探讨CFTR基因M470V多态性与男性不育的关系。方法收集临床诊断明确的轻度少精子症患者66例,重度少精子症患者59例,无精子症患者51例和生育力正常男性120例。外周血基因组DNA抽提,PCR技术扩增CFTR基因外显子10特定片段,Hph I限制性内切酶酶切方法分析M470V基因型和等位基因分布频率,DNA测序检测M470V SNP类型,应用SPSS17.0进行统计学分析,利用卡方检验,P0.05视为有显著性差异。结果 4组比较CFTR基因M470V基因型和等位基因分布频率无统计学差异(P值均0.05)。结论 CFTR基因M470V多态性与少精子症及无精子症无关。     

无精子症和严重少精子症134例遗传学分析

目的：研究无精子症和严重少精子症患者染色体畸变及Y染色体(Yql1区)无精子症因子(azoospermic factor，AZF)缺失情况，建立Y染色体微缺失的临床筛查方法。方法：对134例患者(无精子症97例，严重少精子症37例)经染色体核型分析及AZF、区三个位点8对引物PCR扩增，检测染色体畸变和Y染色体微缺失率。结果：134例中染色体核型异常9例，占6．72％。AZF缺失18例，缺失率为13．43％。无精子症和严重少精子症AZF、缺失率分别为14．43％、10．81％。结论：染色体畸变和Y染色体微缺失是导致无精子症和严重少精子症的主要原因之一。无精子症缺失率高于严重少精子症患者。AZF区三个位点8对引物PCR扩增可作为Y染色体微缺失的临床筛查方法。     

先天性双侧输精管缺如相关致病基因研究进展

先天性双侧输精管缺如(CBAVD)会导致梗阻性无精子症及男性不育,是男性生殖系统先天性畸形的一种.目前公认囊性纤维化跨膜转导调节因子(CFTR)的突变是CBAVD的主要病因,随着研究的深入,发现粘附型G蛋白偶联受体G2(ADGRG2)、溶质载体家族9成员3(SLC9A3)等基因的异常也参与了CBAVD的发生发展.建立合...     

性染色体与男性不育

男性不育是个全球化的问题,其包括遗传原因在内的影响因素众多。对男性而言,X染色体和Y染色体均为单个拷贝。Y染色体因为包含了许多精子发生和性腺发育的关键基因,因而成为研究的热点。Y染色体微缺失是男性精子发生障碍最常见的原因之一。Y染色体长臂的无精子症因子(AZF)区是Y染色体微缺失的好发区域。目前明确定位于AZF区域与精子发生相关的编码蛋白基因有14个,但由于通常的AZF缺失为多基因的联合缺失,因而AZF区域的特定基因在精子发生中的作用还不是很清楚。哺乳动物X染色体在精子发生中的作用因其富集着许多精子发生过程中生殖细胞特异表达基因而受到重视,如AR、USP26、TAF7L、TEX11、KAL1、AKAP4和NXF2等基因。在男性,由于X染色体为半合子状态,X连锁基因通常承受着特别的进化压力,X染色体连锁的单拷贝基因突变不会象常染色体那样被1个正常的等位基因所掩盖掉。尽管许多关于X染色体与精子发生关系的研究已经进行,但X染色体与男性不育的关系仍然还不清楚,还有待更进一步研究。     

CFTR突变基因l不影响先天性梗阻性无精子症患者ICSI治疗的成功率

为探讨囊性纤维化跨膜转运调节物(Cystic Fibrosis Transmembrane Conductance Regulator,CFTR)基因突变是否影响先天性梗阻性无精子症患者单精子卵浆内注射(Intracytoplasmic Sperm Injection,ICSI)治疗的成功率,本文对3例先天性梗阻性无精子症CFTR突变基因携带者和18例CFTR突变基因非携带者进行了ICSI的治疗.结果表明先天性梗阻性无精子症CFTR突变基因携带者与CFIR突变基因非携带者ICSI治疗时受精率、卵裂率和妊娠率无显著性差异.结论CFTR突变基因并不影响先天性梗阻性无精子症患者ICSI治疗的成功率,故这些患者在ICSI治疗前夫妻双方更有必要行CFTR突变基因的筛查.     

男性不育的遗传学评估

无精子症或严重少精子症男性(5×10 6/ml)在接受治疗之前应通过遗传学检测确定其不育的真正原因。正确区分梗阻性无精子症(obstructive azoospermia,OA)与非梗阻性无精子症(non-obstructive azoospermia,NOA)至关重要,因为相比于NOA(睾丸体积小、质地柔软、FSH水平升高),OA(正常的睾丸功能、睾丸体积以及FSH水平)的遗传学检测有所不同。在NOA患者人群中,病史回顾、体格检查和实验室检测对于遗传学检测方法的选择是必须的,尤其针对原发性睾丸衰竭或先天性低促性腺激素型性腺功能低下症的NOA患者。遗传学检测包括由于先天性输精管缺如所致OA的囊性纤维化跨膜传导调节因子的检测,和针对严重少精子症或NOA患者的染色体核型分析、Y染色体微缺失等其他特殊检测方法。这些遗传学检测能够帮助判定哪些患者适合药物和/或手术治疗。最新的遗传学分析技术将有助于男性不育的诊断和掌控。     

Genetics of male infertility

Genetic causes of male infertility increase in frequency with decreasing sperm concentration (oligo-/azoospermia). The decision about genetic tests should be made after a complete andrological work-up. Common causes comprise chromosomal aberrations (including Klinefelter syndrome), microdeletions of the AZF loci of the Y chromosome, mutations in the gene responsible for cystic fibrosis (CFTR) causing CBAVD and in genes involved in hypogonadotropic hypogonadism (including Kallmann syndrome). Every genetic investigation should be accompanied by comprehensive genetic counselling to help with the interpretation of results and support the patient/the couple concerning consequences for their family planning and treatment options.     

Genetik der männlichen Infertilität

Genetic causes of male infertility increase in frequency with decreasing sperm concentration (oligo-/azoospermia). The decision about genetic tests should be made after a complete andrological work-up. Common causes comprise chromosomal aberrations (including Klinefelter syndrome), microdeletions of the AZF loci of the Y chromosome, mutations in the gene responsible for cystic fibrosis (CFTR) causing CBAVD and in genes involved in hypogonadotropic hypogonadism (including Kallmann syndrome). Every genetic investigation should be accompanied by comprehensive genetic counselling to help with the interpretation of results and support the patient/the couple concerning consequences for their family planning and treatment options.     

A novel mutation in the transactivation-regulating domain of the androgen receptor in a patient with azoospermia

Genetic factors including Y chromosome microdeletions and androgen receptor (AR) gene mutations are responsible for male infertility. In the present study, genetic analysis was performed in an infertile Iranian male with azoospermia. Multiplex polymerase chain reaction with 6 sequence-tagged site markers on the Yq11 chromosome revealed no microdeletions in the Y chromosome. Single-strand conformational polymorphism and sequencing analyses detected a 1510C→A transversion in exon 1 of the AR gene, which resulted in a p.Pro504Thr substitution in the transactivation domain of the protein. The present study suggested that mutations in the AR gene might be responsible for some cases of idiopathic infertility, and therefore, molecular analyses may be useful for genetic counseling of candidates with regard to the use of assisted reproductive techniques.     

Genetic evaluation of male infertility

Men with severe oligospermia (<5 million sperm/mL ejaculate fluid) or azoospermia should receive genetic testing to clarify etiology of male infertility prior to treatment. Categorization by obstructive azoospermia (OA) or non-obstructive azoospermia (NOA) is critical since genetic testing differs for the former with normal testicular function, testicular volume (~20 mL), and follicle-stimulating hormone (FSH) (1-8 IU/mL) when compared to the latter with small, soft testes and increased FSH. History and physician examination along with laboratory testing (following appropriate genetic counseling) is critical to accurate selection of genetic testing appropriate for azoospermia due to primary testicular failure as compared with congenital hypogonadotropic hypogonadism (HH). Genetic testing options include cystic fibrosis transmembrane conductance regulator (CFTR) testing for men with congenital absence of the vas, while karyotype, Y chromosome microdeletions (YCMD), and other specific genetic tests may be warranted depending on the clinical context of severe oligospermia or NOA. The results of genetic testing guide management options. The most recent techniques for genetic analysis, including sperm microRNA (miRNA) and epigenetics, are forming the foundation for future genetic diagnosis and therapeutic targets in male infertility.     

Screening of ΔF508 mutation and IVS8-poly T polymorphism in CFTR gene in Tunisian infertile men without CBAVD

It is well established that cystic fibrosis transmembrane conductance regulator gene (CFTR) mutations are involved in congenital bilateral absence of the vas deferens (CBAVD), causing obstructive azoospermia and male infertility. Also, several studies reported a relatively high prevalence of CFTR gene mutations in healthy men presenting reduced sperm quality. In this study, we investigate ΔF508 mutation and IVS8-polyT polymorphism in CFTR gene in Tunisian infertile men without CBAVD. Genetic analyses were performed in 148 infertile patients and 126 fertile individuals. The polymorphic IVS8-polyT tract in CFTR gene was analysed in only 129 infertile patients and 54 individuals of control group. As well, we screened for Y chromosome microdeletions in all infertile patients. No ΔF508 mutation was diagnosed either in infertile patients or in control group. 5T allele of IVS8-polyT tract was found in both infertile men (4.26%) and fertile individuals (8.33%). 5T/5T genotype was observed only in two azoospermic patients without Y microdeletions. The most frequent genotype of IVS8-polyT tract in infertile men and controls was 7T/7T (69.75% and 59.25% respectively). There was no association between IVS8-polyT polymorphism and reduced semen quality. Neither ΔF508 mutation nor 5T allele is involved in pathogenesis of male infertility in Tunisian infertile patients without CBAVD.     

CFTR gene mutations and male infertility

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are a relatively frequent cause of male infertility. Depending on their molecular consequences, CFTR mutations may either result in typical cystic fibrosis (CF), one of the most common autosomal recessive disorders, which is characterized by chronic lung disease, pancreatic exocrine insufficiency, an increase in the concentration of sweat electrolytes and male infertility, due to obstructive azoospermia, or in atypical (often monosymptomatic) forms of CF such as congenital absence of the vas deferens (bi- or unilateral), bilateral ejaculatory duct obstruction or bilateral obstructions within the epididymides. All males with idiopathic obstructive azoospermia bear an increased risk for CF offspring. Couples requesting microsurgical epididymal sperm aspiration and in vitro fertilization, e.g. intracytoplasmic sperm injection, should be offered genetic counselling and molecular genetic analysis of the CFTR gene, if male infertility due to obstructive azoospermia is the underlying cause.     

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.     

Genetic investigations of CFTR mutations in congenital absence of vas deferens, uterus, and vagina as a cause of infertility

A qualitative diagnosis of infertility requires attention to male and female physical abnormalities including endocrine anomalies and genetic conditions that interfere with reproduction. Many genes are likely to be involved in the complex process of reproduction. Congenital bilateral absence of the vas deferens (CBAVD) is a genital form of cystic fibrosis (CF) that is responsible for 2%-6% of male infertility. The incidence of CF varies in different populations; therefore, the incidence of CBAVD will also vary in different populations. The spectrum and distribution of cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations differ between CBAVD and CF patients and are comparable to control individuals. Combinations of particular alleles at several polymorphic loci yield insufficient functional CFTR protein. CFTR mutations are also associated with congenital absence of the uterus and vagina (CAUV). Females with CF are found to be less fertile than normal healthy women. Because of techniques such as intracytoplasmic sperm injection (ICSI), CBAVD patients are now able to father children. Such couples, however, have an increased risk of having a child with cystic fibrosis, and therefore genetic testing and counseling should be provided. Around 10% of obstructive azoospermia is congenital and due to mutations in the CF gene. This review highlights the relationship of mutations in the CFTR gene with CBAVD and CAUV.     

严重少精子症及非梗阻性无精子症患者Y染色体微缺失分析

目的探讨严重少精子症及非梗阻性无精子症与Y染色体长臂微缺失之间的关系。方法该病例对照研究包括216例严重少精子症、189例非梗阻性无精子症患者及100例精液参数正常的对照。采用多重PCR对Y染色体AZFa、AZFb、AZFc及AZFd区域进行检测。玷果在严重性少精子症患者中,AZF总缺失率为10．65％（23／216）,其中以AZFc区缺失最常见,占缺失的78．26％（18／23）;在非梗阻性无精子症患者中,AZF总缺失率为13．76％（26／189）,其中也以AZFc区缺失最常见,占缺失的57．69％（15／26）;在正常对照中发现1例AZFb缺失,两病例组AZF区缺失分别与对照组相比较均具有显著差异（X^2=9．066,P=0．003;X^2=10．74,P=0．001）。结论通过对Y染色体微缺失的检查可以从基因水平寻找生精障碍的原因以及为优生优育提供可靠的遗传信息依据。