Kisspeptin and attributes of infertile males and females: A cross‐sectional study in a subset of Pakistani population

Kisspeptin, a peptide hormone, plays a pivotal role in fertility and neuroendocrine regulation of hypothalamo–pituitary–gonadal axis. Increased kisspeptin and reproductive hormones are responsible for fertility in male and females. This study aimed to explore the role of kisspeptin on hypothalamo–pituitary–gonadal axis by comparing the levels of kisspeptin in fertile and infertile subjects and identifying single nucleotide polymorphisms (SNPs) of KISS1 gene in exon 2 and exon 3 of infertile male and female cohorts. A cross‐sectional study was carried out on 80 males (44 infertile and 36 fertile) and 88 females (44 in each group). Significantly high levels of kisspeptin (KP), follicle‐stimulating hormone (FSH), luteinizing hormone and testosterone were observed in fertile male and female subjects except low FSH levels in comparison with infertile female subjects. One polymorphism in exon 2 (E1225K [G/A 3673]) and three in exon 3 (P1945A [C/G 5833]; Insertion of T at 6075; G2026G [C/G 6078]) in infertile group were detected, with low KP and hormonal levels. Male subjects had abnormal sperm parameters and unsuccessful attempt of intracytoplasmic sperm injection in females. Expression of SNP in exon 2 and exon 3 of KISS1 could be responsible for alteration in release of reproductive hormones and gonadal functions, hence causing infertility.     

生精障碍相关基因单核苷酸多态性研究进展

生精相关基因遗传多态性是生精障碍的一个重要的遗传病因.通过基因敲除技术现已鉴定出大量与精子发生密切相关基因.此类生精障碍基因包括表达酶类、受体类、细胞凋亡类、转录调控类等基因.上述基因的遗传易感性、感染和环境等因素共同作用导致男性非梗阻性无精子症和少精子症.生精障碍相关基因单核苷酸多态性(SNP)分析可从分子水平上阐述...     

Single‐nucleotide polymorphisms in the LRWD1 gene may be a genetic risk factor for Japanese patients with Sertoli cell‐only syndrome

Genetic mechanisms have been implicated as a cause of some cases of male infertility. Recently, ten novel genes involved in human spermatogenesis, including human LRWD1, have been identified by expression microarray analysis of human testictissue. The human LRWD1 protein mediates the origin recognition complex in chromatin, which is critical for the initiation of pre‐replication complex assembly in G1 and chromatin organization in post‐G1 cells. The Lrwd1 gene expression is specific to the testis in mice. Therefore, we hypothesized that mutation or polymorphisms of LRWD1 participate in male infertility, especially azoospermia. To investigate whether LRWD1 gene defects are associated with azoospermia caused by SCOS and meiotic arrest (MA), mutational analysis was performed in 100 and 30 Japanese patients by direct sequencing of the coding regions, respectively. Statistical analysis was performed for patients with SCOS and MA and in 100 healthy control men. No mutations were found in LRWD1; however, three coding single‐nucleotide polymorphisms (SNP1‐SNP3) could be detected in the patients. The genotype and allele frequencies in SNP1 and SNP2 were notably higher in the SCOS group than in the control group (P < 0.05). These results suggest the critical role of LRWD1 in human spermatogenesis.     

单核苷酸多态性与前列腺癌的研究进展

前列腺癌是影响西方国家男性健康的常见恶性肿瘤,而单核苷酸多态性(SNPs)作为第3代遗传标记可以影响到前列腺癌的发生、发展及预后。相同SNPs在不同种族间和前列腺癌的关系可能存在差异;本文就与前列腺癌相关的基因进行分类,描述不同SNPs与前列腺癌的关系。SNPs可以预测前列腺癌治疗过程中可能的不良反应,同时也可预测前列腺癌的患病风险,但目前仍存在一定的局限。     

CYP1A2基因多态性与前列腺癌的相关性研究

目的:评价CYP1A2基因单核苷酸多态性(SNPs)与前列腺癌分期分级的相关性。方法:对253例良性前列腺增生(BPH)患者与206例去势前列腺癌患者CYP1A2基因中rs2069514-3859(A>G)位点及rs2069525-1707(C>T)位点进行基因测序,并对各基因表型与前列腺癌的分期分级相关性进行统计学分析。结果:BPH及去势前列腺癌患者的两种CYP1A2单核苷酸多态性的发生率无明显差异(P>0.05),其基因多态性与前列腺癌的病理分期均无相关性(P>0.05);但rs2069525-1707(C>T)中含C等位基因型的前列腺癌Gleason评分多在7分以下(P=0.030,OR=4.658,95%CI:1.222～17.754)。结论:CYP1A2基因的SNPs与前列腺癌的病理分级之间可能有一定的相关性,但其发生机制及临床意义有待进一步证实及研究。     

ERCC2单核苷酸多态性对宁夏原发性男性不育的影响

目的:探讨DNA修复基因(ERCC2)单核苷酸多态性(SNPs)rs13181、rs1618536和SNPrs1799793对宁夏原发性男性不育的影响。方法:采用病例-对照研究方法,运用MassArray SNP技术,对宁夏地区351例原发性男性不育患者[年龄22~38(31.0±4.2)岁]和327例健康生育对照人群[年龄19~42(33.0±5.9)岁]的ERCC2 SNP rs13181、rs1618536和rs1799793进行分型检测。结果:ERCC2 SNP rs13181、rs1618536和rs1799793基因型频率和等位基因频率在病例组和对照组中的分布无统计学意义(P0.05),其中AnyG-anyA-anyA突变基因型频率在两组中分布具有统计学差异(OR=0.414,95%CI=0.176~0.970)。结论:ERCC2 SNP rs13181、rs1618536和rs1799793在宁夏地区男性原发性不育中存在交互作用,随着联合突变位点的增多,不育症的发病风险增加。     

eNOS gene T786C,G894T and 4a4b polymorphisms and male infertility susceptibility: a meta‐analysis

The association between polymorphism of eNOS and male infertility in several studies was controversial. To explore a more precise estimation of the association, a meta‐analysis of eight case–control studies, including 1,968 cases and 1,539 controls, were selected. The meta‐analysis was conducted by calculating the pooled odds ratio (OR) with a 95% confidence interval (95% CI). Overall, the association between T786C and risk of male infertility was obvious (TC vs. TT: OR, 1.20; 95% CI, 1.01–1.42; CC vs. TT: OR, 3.37; 95% CI, 1.65–6.87; TC/CC vs. TT: OR, 1.47; 95% CI, 1.25–1.73; CC vs. TT/TC: OR, 3.18; 95% CI, 1.54–6.56; TC vs. TT: OR, 1.65; 95% CI, 1.27–2.03). However, no overall association was observed between the other two polymorphisms of eNOS (G894T and 4a4b) and male infertility. Stratified analysis showed that significantly strong association between T786C polymorphism and semen quality was present in all three types of male infertility (azoospermia, oligozoospermia and asthenozoospermia). In the subgroup analysis based on ethnicity, both T786C and 4a4b could influence the risk of male infertility in Asian and Caucasian. Further studies of polymorphisms of eNOS with their biological functions are needed to understand the role in the development of male infertility.     

Y chromosome microdeletions and varicocele as aetiological factors of male infertility: A cross‐sectional study

The pathogenic mechanisms by which varicocele disrupt spermatogenesis are not clearly understood. Over 30% of male infertility cases resulting from spermatogenic problems are associated with genetic abnormalities, and Y chromosome microdeletions are the second most frequent genetic cause. Here, we aimed to evaluate the frequency of Y chromosome microdeletion in infertile men with varicocele. A cross‐sectional study comprising 51 infertile men with varicocele presenting spermatogenesis failures was performed. Y chromosome microdeletion research was made using polymerase chain reaction. Of the 51 men with infertility and varicocele, 35.3% (18/51) had nonobstructive azoospermia and 64.7% had severe oligozoospermia. Y chromosome microdeletion was found in two cases (3.9%): one patient had nonobstructive azoospermia and complete microdeletion of the AZFb and AZFc regions, and another patient had severe oligozoospermia and complete microdeletion of the AZFc region. Although in recent years, a genetic aetiology related to Y chromosome microdeletions has become a major cause of infertility in males with spermatogenesis failures, in this study, the varicocele was the clinical cause of seminal abnormalities that could lead to infertility, suggesting that both varicocele and Y chromosome microdeletion aetiologies can present, alone or combined, as factors of male infertility.     

Association of polymorphisms of A260G and A386G in DAZL gene with male infertility: a meta-analysis and systemic review

To investigate the association of single nucleotide polymorphism 260 and 386 (SNP260 and SNP386) gene with male infertility, an electronic search was performed to identify case-control studies evaluating the relationship of SNP260 or SNP386 of deleted in azoospermia-like (DAZL) and male infertility. Review Manager 5 was used to process the meta-analysis and other statistical analysis. A total of 139 records were retrieved, of which 13 case-control studies with total 2715 patients and 1835 normozoospermic men were included. SNP260 was found not to play a functional role in male oligo/azoospermia either for Caucasians or for Asians. But for SNP386, models of allele (A/G), dominant (AA/AG + GG), co-dominant (AA/AG) and super-dominant (AA + GG/AG) had a strong correlation to spermatogenic failure with related odds ratio being 0.15 (95% confidence interval [95% CI] 0.07 to 0.34, P < 0.00001), 0.16 (95% CI 0.07 to 0.35, P < 0.00001), 0.15 (95% CI 0.06 to 0.33, P < 0.00001) and 0.15 (95% CI 0.06 to 0.33, P < 0.00001), respectively. Moreover, this correlation was only found in the Chinese Han population (decreasing around 85% risk of oligo/azoospermia infertility) and not found in India, Japan, and Caucasian countries. Our analysis demonstrated that SNP260 of DAZL did not contribute to oligo/azoospermia while SNP386 was correlated to male infertility. However, this correlation was only found in China with a country-specific and ethnicity-specific manner.     

Association between two single nucleotide polymorphisms of interleukin‐27 gene and increased cryptorchidism risk

Growing evidences have suggested the association between interleukin‐27 and cryptorchidism. We aimed to investigate the relationship between IL‐27 polymorphisms and cryptorchidism susceptibility. A total of 519 males were enrolled in a case–control study (150 cases and 369 normal subjects). The variants were discriminated using polymerase chain reaction–restriction fragment length polymorphism methods. The proportions of the major allele for rs153109 and rs17855750 were A and T with frequencies of 0.56 and 0.85 in cases and 0.51 and 0.91 in controls respectively (P values = 0.002, P value = 0.002). The heterozygous genotype of rs153109 and 17855750 was A/G and T/G with frequencies of 0.62 and 0.25 in cases and 0.39 and 0.17 in controls respectively (P values <0.001, P values <0.001). The A allele and A/G genotype of rs153109 polymorphisms contribute to increase cryptorchidism susceptibility, and G allele and T/G genotype of rs17855750 also contribute to increase cryptorchidism susceptibility, which implies that these allele and genotypes may be risk factors for the development of cryptorchidism.     

中国人群尿道下裂DGKK基因多态性的研究

目的:探讨甘油二脂激酶κ(DGKK)基因单核苷酸多态性在中国人群尿道下裂发病的作用。方法:收集300例散发国内尿道下裂患儿(200例中远端型,100例近端型)和200例正常儿童的外周静脉血,提取DNA,对DGKK基因的2个在中国人群中尚未报道的与尿道下裂发生相关的单核苷酸多态性位点(SNP)rs1934179和rs7063116进行直接测序并比对。结果:病例组的rs1934179的突变型频率(5.0%,15/300)显著高于对照组(1.5%,3/200)(P0.05),rs7063116的突变型频率(5.67%,17/300)亦显著高于对照组(2.0%,4/200)。而病例组中,rs1934179和rs7063116均为仅中远端型尿道下裂组的突变型频率(6.5%,13/200;7.5%,15/200)显著高于对照组(P0.05),而近端型尿道下裂组的突变型频率(均为2.0%,2/100)与对照组没有统计学差异(P0.05)。结论:DGKK基因的多态性可能和中国人群尿道下裂的发生存在联系,尤其是与中远端型尿道下裂的发生明显相关。     

hOGG1 gene polymorphism and breast cancer risk: A systematic review and meta‐analysis study

To address the effect of hGGO1 (rs1052133) gene polymorphism on the risk of breast cancer, a meta‐analysis was performed. We pooled adjusted odds ratios (OR) as overall and three subgroups (menopausal status, ethnicity, and study setting). In overall analysis, we found a significant association when the model of inheritance was homozygote (pooled OR 1.14; 95% CI 1.01, 1.29). Subgroup analysis showed significant association for homozygote genetic models among postmenopause women (OR 1.23; 95% CI 1.01, 1.49) and Asian population (OR 1.17; 95% CI 1.01, 1.35). This study suggested that the carrier of Ser326Cys polymorphism of hOGG1, Cys/Cys vs Ser/Ser, are at higher risk for breast cancer, independent of other hormonal and environmental risk factors.     

Single nucleotide polymorphism C677T in the methylenetetrahydrofolate reductase gene might be a genetic risk factor for infertility for Chinese men with azoospermia or severe oligozoospermia

Aim： To analyze the distribution of the single nucleotide polymorphism （SNP） C677T in the methylenetetrahydrofolate reductase （MTHFR） gene in 355 infertile Chinese patients with idiopathic azoospermia or severe oligozoospermia and 252 fertile Chinese men as controls to explore the possible association of the SNP and male infertility. Methods： Using the polymerase chain reaction （PCR）-restriction fragment length polymorphism technique, the allele and genotype distribution of SNP C677T in the MTHFR gene were investigated in both patients and controls. Results： The frequencies of allele T （40.9% vs 30.4%, P = 0.002, odds ration [OR] = 1.58, 95% confidence interval [CI]： 1.24-2.02） and mutant homozygote （TT） （18.3% vs. 11.5%, P = 0.023, OR = 1.72, 95% CI： 1.07-2.76） as well as carrier with allele （TT ＋ CT） （63.4% vs. 49.2%, P = 0.0005, OR = 1.79, 95% CI： 1.29-2.48） in infertile patients were significantly higher than those in controls. After patient stratification, the significant differences in distribution of the SNP between each patient subgroup and control group still remained. Conclusion： Our findings indicate that there is an association of SNP C677T in the MTHFR gene with male infertility, suggesting that this polymorphism might be a genetic risk factor for male infertility in Chinese men.     

A large‐scale replication study for the association of rs17039192 in HIF‐2α with knee osteoarthritis

Osteoarthritis (OA) is a common disease with a genetic component for its etiology. Recently, a genetic association of a single nucleotide polymorphism (SNP), rs17039192 in HIF‐2α with knee OA has been reported in a Japanese population; however, controversy exits for its replication and a role of HIF‐2α in OA. This study aimed to evaluate the association of the SNP by a large‐scale replication study. A total of 8,457 subjects (3,129 OA cases and 5,328 controls) from seven independent cohorts from six countries (Japan, China, Taiwan, Korea, Greece, and Australia) were recruited and genotyped. The association of rs17039192 with knee OA was evaluated by meta‐analyses. The association of the HIF‐2α SNP was not replicated in any of the populations. Contrary to the previous report, the odds ratios (ORs) of the risk allele frequency were all less than 1. A combined analysis for the seven populations also showed no replication of the association (OR = 0.91, 95% confidence interval = 0.81–1.03). Our large‐scale meta‐analysis showed that the association of rs17039192 in HIF‐2α with knee OA is negative. The significance of HIF‐2α in human OA (idiopathic OA as a common disease) should be further evaluated carefully. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1244–1248, 2012     

Glutathione S‐transferase Mu‐1 gene polymorphism in Egyptian patients with idiopathic male infertility

The aim of this study was to examine whether an association exists between glutathione S‐transferase Mu‐1 (GSTM1) gene polymorphism and idiopathic male infertility. Sixty men with primary idiopathic infertility and 60 fertile men, serving as controls, were recruited for the study. The polymorphism was analysed using polymerase chain reaction–restriction fragment length polymorphism (PCR‐RFLP) technique. The frequency of GSTM1 null genotype was observed to be higher in infertile men 40% in comparison with 33.3% in the fertile men, but this difference was not statistically significant. There was statistically significant difference between cases and controls as regards GSTM1 genotype distribution (^MCP = 0.006*) in GSTM1‐positive men. Patients with the GSTM1 null genotype had significantly lower sperm concentrations and total sperm count when compared with patients with GSTM1‐positive genotype. In the control group, men with GSTM1 null genotype had significantly lower sperm concentrations but not total sperm count when compared with men with GSTM1‐positive genotype. The results of this study suggest a possible negative effect of GSTM1 null genotype on the spermatogenic potential of the testis.     

The role of TNXB single‐nucleotide polymorphisms in recurrent shoulder dislocation

Tenascin‐X (TNX) is an extra‐cellular matrix glycoprotein associated with collagen fibril deposition. Recent reports have linked truncated TNX mutations (TNXB) to generalized joint hypermobility and most importantly recurrent joint dislocation. In the present study, we investigated whether there is an association between joint dislocation recurrence rate and the frequency of TNXB single‐nucleotide polymorphisms (SNPs). Seventy‐eight patients treated for post‐traumatic shoulder instability and 82 healthy controls were genotyped for selected TNXB SNP using TaqMan® Genotyping Assays. At a mean follow‐up of 24 months recurrence rate and clinical outcomes were evaluated using the Constant and Murley, Rowe, and DASH scores. The association between genotypes and joint dislocation was tested using the dominant, recessive and additive models, and the model‐free approach. Genotype distribution of the examined SNPs did not significantly deviate from the Hardy–Weinberg equilibrium (HWE) neither in patients nor in the controls. Moreover, there was no significant difference in genotype and allele distribution between patients and controls. Finally, no difference in genotype frequency was detected between patients who experienced a re‐dislocation after the initial surgery and patients who did not sustain a re‐dislocation. The SNPs investigated in this study have no clinically relevant influence on TNXB gene expression and/or TNX function. Therefore, these SNPs could not be used for predicting individual risk of recurrent shoulder dislocation. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 295–299, 2013     

ACP1 genetic polymorphism and spermatic parameters in men with varicocele

Platelet‐derived growth factor (PDGF) and its receptors (PDGFRs) play a key role in the regulation of the embryonic and postnatal development of male gonads. PDGF deficiency is associated with severe spermatogenic impairment. ACP₁ is a phosphoprotein tyrosine phosphatase that is able to dephosphorylate PDGFR, decreasing its activity as growth factor. The enzyme is polymorphic and shows strong differences in enzymatic activity among genotypes. At the Outpatient Department for Infertility, University of Rome La Sapienza, we investigated the effect of high‐activity ACP₁ genotype on spermatic parameters in 105 subjects referred to for varicocele. ACP₁ genotype was determined by DNA analysis. In ACP₁ *B/*C genotype, which shows the highest enzymatic activity, spermatic concentration is significantly lower and atypical spermatozoa are significantly more frequent as compared to other ACP₁ genotypes. It is concluded that subjects carrying *B/*C genotype who represent about 10% of the population have a severe impairment of spermatic parameters in the presence of varicocele.     

Single nucleotide polymorphisms in succinate dehydrogenase subunits and citrate synthase genes: association results for impaired spermatogenesis

Evaluation of the possible implication of the SDHA, SDHB, SDHC, SDHD and CS genes in non-obstructive male infertility was performed on the basis that sperm concentration in the ejaculate has been previously correlated with nuclear-encoded mitochondrial enzyme activities (the four subunits of succinate dehydrogenase/complex II of the respiratory chain and citrate synthase). We performed an exhaustive analysis of the five genes for the presence of sequence variants that could be associated with impairment of sperm production. blastn searches in the genomic sequence NCBI database evidenced the presence of highly homologous sequences elsewhere on the genome that can interfere with polymerase chain reaction experiments. Therefore, a careful design of the analytical strategy to search for sequence variants was performed. In this report, we provide primer sequences that allowed selective amplification of coding and immediate flanking regions of the five genes. Fifty-five sequence variations in the five genes were identified in infertile and normozoospermic fertile individuals as controls and only one of them (SDHA c.456+32G>A) showed significant genotype association with impairment of sperm production. Moreover, new single nucleotide polymorphisms identified should be useful in future association studies for other human diseases related to nuclear-encoded genes, leading to mitochondrial respiratory chain activity impairment revealing the physiological role of these genes.