Risk Of Non-obstructive Azoospermia Research Articles

Association Study Between Polymorphisms of PRMT6, PEX10, SOX5, and Nonobstructive Azoospermia in the Han Chinese Population1

A previous genomewide association study of nonobstructive azoospermia (NOA) in the Han Chinese population identified three risk loci (rs12097821, rs2477686, and rs10842262) and provided strong evidence for a genetic influence in male infertility. However, recently, a follow-up study of these single nucleotide polymorphism (SNP) loci in the Japanese population showed that none of them were significantly associated with NOA. Therefore, we conducted an association study, consisting of 550 NOA cases and 555 normal controls, to further validate whether the risk of those three SNPs still existed in an independent Han Chinese male population. The association studies did not support the association of rs12097821 and rs2477686 with NOA for both genotype and allele distributions, but rs10842262 in the SOX5 gene was significantly associated with NOA (chi square = 9.31; P = 0.0095 and chi square = 9.27; P = 0.0023, respectively). Our study provides genetic evidence for SOX5 polymorphism in NOA, contributing to predicting males at high risk of NOA in Han Chinese population. Considering genetic differences among populations, future validating studies in independent samples are suggested.

Genetic variants in Ser-Arg protein–coding genes are associated with the risk of nonobstructive azoospermia in Chinese men

To evaluate the association between genetic variants in Ser-Arg (SR) protein-coding genes and the susceptibility of nonobstructive azoospermia (NOA) in Chinese men. Case-control study. State Key Laboratory of Reproductive Medicine in Nanjing Medical University conducted the genotyping and examined the expression levels of genes. The study included 962 NOA patients and 1,931 control subjects. None. Genotyping of 16 single-nucleotide polymorphisms (SNPs) of eight "canonic" SR protein-coding genes were performed with the use of the Illumina Infinium Beadchip platform. Odds ratios were calculated by logistic regression analysis in the additive model. Expression levels were measured by quantitative reverse-transcription polymerase chain reaction. Rs17431717 near SFRS9 and rs12046213 near SFRS4 were significantly associated with a decreased risk of NOA, whereas rs10849753 near SFRS9 and rs6103330 in SFRS6 were associated with an increased risk of NOA. Of the two SNPs in SFRS9, only rs17431717 remained significant after conditioning on another. Combined analysis of three promising SNPs (rs17431717, rs12046213, and rs6103330) showed that compared with individuals with "0-2" risk alleles, those carrying "3," "4," and "≥ 5" risk alleles had 1.22-, 1.38-, and 1.90-fold increased risk of NOA, respectively. Polymorphisms in SR protein-coding genes may contribute to the risk of NOA in Chinese men. The findings of this study can help us to further understand the etiology of spermatogenic impairment, and they provide more evidence for the role of splicing activity in human spermatogenesis.

Comprehensive pathway-based analysis identifies associations of BCL2, GNAO1 and CHD2 with non-obstructive azoospermia risk

Do genetic variants in known canonical pathways that have been widely suggested to affect spermatogenesis confer susceptibility to non-obstructive azoospermia (NOA)? Rs1406714 in CHD2, rs2126986 in GNAO1 and rs7226979 in BCL2 were associated with NOA in Han Chinese men at a significant level after multiple testing corrections. Previous genome-wide association studies (GWASs) have identified three loci for NOA, whereas less attention has been given to those markers that did not exceed the genome-wide significance threshold. We conducted a two-stage association study containing 1653 NOA cases and 2329 controls to investigate the susceptibility markers for NOA. Imputation and pathway-based approaches can be applied to identify additional causal makers with small effects on NOA. We performed a candidate pathway-based association study using imputed-genotyping data for 24 238 single nucleotide polymorphisms estimated from NOA GWAS. Remarkably, 40 markers were associated with NOA in both imputation analysis and NOA GWAS (Stage 1) after linkage disequilibrium analysis and selected for validation (Stage 2) in another population. Based on the literature, genes from 11 biological pathways known or hypothesized to be important in spermatogenesis were selected. Combined analysis using directly genotyped data for Stages 1 and 2 revealed that rs1406714 in CHD2 was associated with decreased risk of NOA [odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.68-0.89, Pmeta = 1.7E-04], whereas rs2126986 in GNAO1 and rs7226979 in BCL2 were both risk makers for NOA (rs2126986: OR = 1.28, 95% CI = 1.15-1.41, Pmeta = 2.3E-06; rs7226979: OR = 1.21, 95% CI = 1.11-1.33, Pmeta = 4.5E-05). Our analysis of genes in the pathways studied was not exhaustive. Our study opens new avenues for the identification of other novel causal markers that are related to NOA. It will also provide a new paradigm for understanding the etiology of male infertility and contribute to the development of targeted therapies.

Evaluation of Five Candidate Genes from GWAS for Association with Oligozoospermia in a Han Chinese Population

BackgroundOligozoospermia is one of the severe forms of idiopathic male infertility. However, its pathology is largely unknown, and few genetic factors have been defined. Our previous genome-wide association study (GWAS) has identified four risk loci for non-obstructive azoospermia (NOA).ObjectiveTo investigate the potentially functional genetic variants (including not only common variants, but also less-common and rare variants) of these loci on spermatogenic impairment, especially oligozoospermia.Design, Setting, and ParticipantsA total of 784 individuals with oligozoospermia and 592 healthy controls were recruited to this study from March 2004 and January 2011.MeasurementsWe conducted a two-stage study to explore the association between oligozoospermia and new makers near NOA risk loci. In the first stage, we used next generation sequencing (NGS) in 96 oligozoospermia cases and 96 healthy controls to screen oligozoospermia-susceptible genetic variants. Next, we validated these variants in a large cohort containing 688 cases and 496 controls by SNPscan for high-throughput Single Nucleotide Polymorphism (SNP) genotyping.Results and LimitationsTotally, we observed seven oligozoospermia associated variants (rs3791185 and rs2232015 in PRMT6, rs146039840 and rs11046992 in Sox5, rs1129332 in PEX10, rs3197744 in SIRPA, rs1048055 in SIRPG) in the first stage. In the validation stage, rs3197744 in SIRPA and rs11046992 in Sox5 were associated with increased risk of oligozoospermia with an odds ratio (OR) of 4.62 (P = 0.005, 95%CI 1.58-13.4) and 1.82 (P = 0.005, 95%CI 1.01-1.64), respectively. Further investigation in larger populations and functional characterizations are needed to validate our findings.ConclusionsOur study provides evidence of independent oligozoospermia risk alleles driven by variants in the potentially functional regions of genes discovered by GWAS. Our findings suggest that integrating sequence data with large-scale genotyping will serve as an effective strategy for discovering risk alleles in the future.

Pathogenic variants screening in five non-obstructive azoospermia-associated genes

Non-obstructive azoospermia (NOA) is one of the most severe forms of male infertility and a recent, genome-wide association study (GWAS) has identified four risk loci associated with NOA. However, a large portion of the heritability of NOA has not been well explained by GWAS. By hypothesizing that rare, low-frequency and common genetic variants might point toward a causal relation between candidate genes and NOA, we performed a two-stage study including deep exon sequencing in 96 NOA cases and 96 healthy controls and a replication study in a larger population containing 522 NOA cases and 484 healthy controls. In the solexa sequencing stage, a total of two rare mutations (chr20. 1902132 and chr20. 1902301 in SIRPA), four common mutations (rs1048055 and rs2281807 in SIRPG, rs11046992 and rs146039840 in SOX5) were identified by using next generation sequencing (NGS). In the validation stage, subjects in the NOA group had a significantly decreased frequency of the heterozygous GA genotype in SIRPA (4.23%, 22 out of 520) than that in the control group (8.60%, 41 out of 477) [odds ratios (OR) 0.47, 95% confidence intervals (CI) 0.28-0.80] (P = 6.00 × 10(-3)). The rs1048055 in SIRPG was associated with a significantly increased risk of spermatogenic impairment, compared with the CC genotype (OR 3.93, 95% CI 1.59-9.70) (P = 3.00 × 10(-3)). Our study provides evidence of independent NOA risk alleles driven by variants in the protein-coding sequence of two of the genes (SIRPA and SIRPG) discovered by GWAS. Further investigation in larger populations and functional characterizations are needed to validate our findings.

A genome-wide association study in Chinese men identifies three risk loci for non-obstructive azoospermia

Non-obstructive azoospermia (NOA) is one of the most severe forms of male infertility. Its pathophysiology is largely unknown, and few genetic influences have been defined. To identify common variants contributing to NOA in Han Chinese men, we performed a three-stage genome-wide association study of 2,927 individuals with NOA and 5,734 controls. The combined analyses identified significant (P < 5.0 × 10(-8)) associations between NOA risk and common variants near PRMT6 (rs12097821 at 1p13.3: odds ratio (OR) = 1.25, P = 5.7 × 10(-10)), PEX10 (rs2477686 at 1p36.32: OR = 1.39, P = 5.7 × 10(-12)) and SOX5 (rs10842262 at 12p12.1: OR = 1.23, P = 2.3 × 10(-9)). These findings implicate genetic variants at 1p13.3, 1p36.32 and 12p12.1 in the etiology of NOA in Han Chinese men.