Search

Nonobstructive azoospermia (NOA) is a severe form of male infertility. The molecular basis of NOA is still poorly understood. The aim of this study was to explore the associations between single nucleotide polymorphisms (SNPs) of the TATA-box binding protein associated factor 4b (TAF4B) gene and NOA. A total of 100 Han Chinese patients with NOA and 100 healthy men as controls were recruited. Targeted gene capture sequencing was performed. A total of 11 TAF4B SNPs were screened in the NOA and control subjects. Six synonymous and 4 nonsynonymous variants were detected. The c.11G>T (p.G4V) mutation was detected only in NOA patients. Polymorphism Phenotyping v2 and Sorting Intolerant From Tolerant analysis indicated that the p.G4V mutation influenced the protein structure of TAF4B. Haplotype analysis showed that the candidate SNPs did not independently associate with NOA and were found at extremely low frequencies in the subject population. Mutation Taster analysis indicated that the c.11G>T/p.G4V mutation was damaging. WebLogo analysis showed that the residue at amino acid 4 was relatively conserved. The p.Gly4Val substitution may affect the structure of the TAF4B protein. The c.11G>T mutation of the TAF4B gene may be associated with NOA in a Chinese population. Bioinformatics analysis indicated this variation may play an important role in the process of spermatogenesis.

Background: Non-obstructive azoospermia (NOA), a serious phenotype of male spermatogenesis failure, is a multifactorial disease which is regulated by genetic, epigenetic, and environmental factors. Some gene structural variants have been demonstrated to be related to NOA. Loss-of-function mutations of KISS1R cause normosmic idiopathic hypogonadotropic hypogonadism (IHH) which result in azoospermia at the pre-testicular level. The objective of this research was to investigate genetic variants of KISS1R in NOA patients., Methods: The entire coding region of 52 spermatogenesis-associated genes (KISS1R included) was sequenced from 200 NOA patients. Mutation screening was performed to identify genetic variations of these genes by targeted exome sequencing. Sequencing data analysis was carried out by a series of bioinformatics tools. Candidate variants confirmation was performed by Sanger sequencing. Functional analysis of candidate variants was evaluated using SIFT and PolyPhen-2., Results: Three heterozygous missense variants in KISS1R were identified in three patients, respectively. No deleterious variations in other candidate genes were found in the three patients. Two of these three variants, p.A211T and p.G186E, had been reported in the ExAC and dbSNP database, respectively, while the other variant p.A301D was novel. These variants were all predicted to be likely pathogenic by in silico analysis., Conclusion: Our study revealed three heterozygous missense variants in KISS1R which expanded the mutation spectrum of KISS1R in infertile men with NOA in the northeast of China., (© 2019 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals, Inc.)

Isodicentric Y chromosomes are considered one of the most common structural abnormalities of the Y chromosome. Neocentric marker chromosomes, with neocentromeres, have drawn increasing attention in recent years. The present study reported an azoospermic male with a neocentric isochromosome Yp, neo(Yp), and an isodicentric Yq, idic(Yq). The karyotype was analyzed using G‑banding, chromosome microarray analysis (CMA), and fluorescence in situ hybridization (FISH) with various detection probes, including sex‑determining region on the Y chromosome (SRY) and Y centromeric, applied at the same time. G‑banding initially revealed the karyotype 47,X,i(Y)(q10),+mar. CMA indicated the presence of an extra Y chromosome, seemingly equivalent to 47,XYY males. FISH delineated the existence of two centromeres on the idic(Yq). For the marker chromosome, two SRY signals were detected instead of the Y‑specific centromere signal, and a visual centromere was observed. This indicated the possible existence of a neocentromere in the marker chromosome, located in the connected region in Yp11.2 band. Finally, the patient's karyotype was established as 47,X,idic(Y)(p11.2), neo(Y)(pter→Yp11.2::Yp11.2→pter). The findings suggested that both idic(Yq) and neo(Yp) could be the main causes of the patient's azoospermia, despite the fact that the partial disomy of Ypter to Yp11.2 did not lead to any major malformations. The present study not only improves the understanding of karyotype/phenotype relationships between neocentric marker Y chromosomes and male infertility, but also supports the hypothesis that the combined application of molecular cytogenetic analysis could aid in reliably confirming breakpoints, origins, and the constitution of the marker chromosomes.

Background: To evaluate the safety of intracytoplasmic sperm injection (ICSI) for men with Y chromosome azoospermia factor (AZF) microdeletions., Methods: Twenty-five men with Y chromosome microdeletions and their partners underwent ICSI treatment. These subjects were matched against 50 ICSI cycles in which the patients had normal Y chromosomes., Results: Among the 25 couples, 17 achieved a clinical pregnancy of which 14 continued to a live birth. Sixteen men had deletions of AZFc markers (sY152, sY254, and sY255), 1 had a deletion of sY152, 3 had a deletion of sY254, sY255, 1 had a deletion of sY152, sY239, Sy242, sY254, and sY255, and 3 had deletions of sY152, sY254, sY255, and sY157. AZFb microdeletions (sY127, sY134, and sY143) were found in 1 patient. AZF microdeletions had no adverse effects on the clinical pregnancy, implantation or delivery rates, birth weight, gestational age, or sex ratio when compared with the control group. Overall, the multiple gestation and preterm delivery rates of the AZF microdeletion group were similar to those in the control group., Conclusion: Men with AZF microdeletions can achieve the delivery of healthy children using ICSI. In this series, it produced good implantation rate and obstetric and perinatal outcomes.

BACKGROUND This study aimed to screen common and low-frequency variants of nonobstructive azoospermia (NOA)-associated genes, and to construct a database for NOA-associated single nucleotide variants (SNVs). MATERIAL AND METHODS Next-generation sequencing of 466 NOA-associated genes was performed in 34 patients with NOA (mean age, 29.06±4.49 years) and 40 sperm donors (mean age, 25.08±5.75 years) from the Han population of northeast China. The SNV database was constructed by summarizing NOA non-negatively-associated SNVs showing statistical differences between NOA cases and controls, and then selecting low-frequency variants using Baylor's pipeline, to identify statistically valid SNVs. RESULTS There were 65 SNVs identified that were significantly different between both groups (p<0.05). Five genetic variants showed positive correlations with NOA: MTRR c.537T>C (rs161870), odds ratios (OR), 3.686, 95% confidence interval (CI), 1.228-11.066; MTRR, c.1049A>G (rs162036), OR, 3.686, 95% CI, 1.228-11.066; PIWIL1, c.1580G>A (rs1106042), OR, 4.737, 95% CI, 1.314-17.072; TAF4B, c.1815T>C (rs1677016), OR, 3.599, 95% CI, 1.255-10.327; and SOX10 c.927T>C (rs139884), OR, 3.192, 95% CI, 1.220-8.353. Also, 52 NOA non-negatively associated SNVs and 39 SNVs were identified by Baylor's pipeline and selected for the SNV database. CONCLUSIONS Five genetic variants were shown to have positive correlations with NOA. The SNV database constructed contained NOA non-negatively associated SNVs and low-frequency variants. This study showed that this approach was an effective strategy to identify risk alleles of NOA.

Rationale: Small supernumerary marker chromosomes (sSMCs) can be usually discovered in the patients with mental retardation, infertile couples, and prenatal fetus. We aim to characterize the sSMC and explore the correlation between with sSMC and male infertility., Patient Concerns: A 26-year-old Chinese male was referred for infertility consultation in our center after 1 year of regular unprotected coitus and no pregnancy., Diagnosis: Cytogenetic G-banding analysis initially described a mosaic karyotype 47,X,Yqh-,+mar[28]/46,X,Yqh-[22] for the proband, while his father showed a normal karyotype. The chromosome microarray (CMA) analysis showed there existed a duplication of Yp11.32q11.221, a deletion of Yq11.222q12, a duplication of 20p11.1 for the patient. Azoospermia factor (AZF) microdeletion analysis for the patient showed that he presented a de novo AZFb+c deletion. Fluorescence in situ hybridization further confirmed the sSMC was an sSMC(Y) with SRY signal, Y centromere, and Yq deletion., Interventions: The patient would choose artificial reproductive technology to get his offspring according to the genetic counseling., Outcomes: The sSMC in our patient was proved to be an sSMC(Y), derived from Yq deletion. The spermatogenesis failure of the proband might be due to the synthetic action of sSMC(Y) mosaicism and AZFb+c microdeletion., Lessons: It is nearly impossible to detect the chromosomal origin of sSMC through traditional banding techniques. The molecular cytogenetic characterization could be performed for identification of sSMC so that comprehensive genetic counseling would be offered.

BACKGROUND Genetic defects are commonly observed in infertile males, although the majority of cases remain idiopathic. In recent years, the relationship between single-nucleotide polymorphisms (SNPs) and male infertility has received increasing attention. The objective of this study was to explore the relationship between non-obstructive azoospermia (NOA) and single-nucleotide polymorphisms in the angiotensin-converting enzyme gene (ACE) using ligase detection reaction (LDR)-PCR. MATERIAL AND METHODS A retrospective study was performed and we screened 4 ACE SNPs (rs4316, rs4331, rs4343, and rs4362) in 121 NOA cases and 256 control subjects by LDR-PCR. The relationship between SNPs and NOA was analyzed. RESULTS ACE SNPs were in Hardy-Weinberg equilibrium (P=0.089 for rs4331, P=0.089 for rs4343, P=0.089 for rs4316, and P=0.381 for rs4362). The allelic and genotypic frequencies of the 4 SNPs were not significantly different between cases and controls (P=0.123 for rs4331, P=0.123 for rs4343, P=0.123 for rs4316, and P=0.179 for rs4362). Haplotype analysis showed the existence of 3 haplotypes, TGAC, CAGT, and TGAT, which showed statistical significance of 0.889, 0.889, and 0.781, respectively, between cases and controls. CONCLUSIONS No significant association was found between ACE SNPs rs4316, rs4331, rs4343, or rs4362 and NOA in the Chinese Han population of Northeast China.

BACKGROUND Genetic mechanisms are associated with male infertility, but the association with non-obstructive azoospermia (NOA) remains unclear. Mutations in the chloride channel accessory 4 (CLCA4) gene have been shown to have a role in male infertility. The aim of this study was to investigate the associations between single nucleotide polymorphisms (SNPs) of the CLCA4 gene and NOA in a Chinese Han population of Northeast China using combined targeted gene capture next-generation sequencing and bioinformatics analysis. MATERIAL AND METHODS The study group included 100 men with NOA, and there were 100 normal controls. Targeted gene capture next-generation sequencing was performed combined with bioinformatics analysis. Ten CLCA4 SNPs were screened in the cases of NOA and control subjects. The associations between SNPs and NOA were analyzed. RESULTS Six SNPs, c.390C>T (rs190628533), c.1474A>G (rs2231599), c.2105C>G (rs757773924), c.2371A>T) (rs759981524), c.956G>A (rs763334876), and c.895T>C (rs79822589) were identified in the study group of cases in NOA but not in control subjects. All CLCA4 SNPs were in Hardy-Weinberg equilibrium. The allele and genotype frequencies of the six SNPs were not significantly different between the study group and the controls. Haplotype analysis showed the existence of two haplotypes, CTAGACTACG and CTCGACTACG, which showed statistical significance of 0.074, and 0.088 between cases of NOA and the controls, respectively. CONCLUSIONS There were no significant associations between CLCA4 SNPs and NOA in men in a Chinese Han population of Northeast China.

Background: Nonobstructive azoospermia (NOA) is one of the most severe forms of male infertility because of impaired spermatogenesis with the absence of spermatozoa in the ejaculate. The causes of this disease can be partly attributed to genetic factors. Some common structural variants and single nucleotide polymorphisms (SNPs) were reported to be associated with NOA. However, the underlying etiology and genetic mechanism(s) remain largely unclear. The aim of this study was to investigate the associated mutations of spermatogenic genes in Chinese infertile men with NOA., Methods: The entire coding region of 25 genes associated with spermatogenesis was sequenced from 200 infertile men with NOA. Screening was carried out using the targeted exome sequencing to identify genetic variations and SNPs of the entire coding region of these genes., Results: After the targeted exome sequencing data were filtered through several currently existing variation databases, a series of variations were found. In this paper, we report one novel stopgain variation c.G992A (p.W331X) in the exon 4 of TACR3 gene. The variant was heterozygous and categorized as pathogenic., Conclusion: In conclusion, our study revealed a novel stopgain mutation c.G992A (p.W331X) in TACR3 which expanded the mutation spectrum of TACR3 in Chinese NOA infertile men and advanced our understanding of the genetic susceptibility to NOA., (© 2018 Wiley Periodicals, Inc.)

Objective: This study aimed to assess the value of measuring the tubule diameter during microdissection testicular sperm extraction (micro-TESE) in predicting outcomes in patients with Sertoli cell-only syndrome (SCOS)., Methods: Fifty-six consecutive patients with SCOS were included. Patients were classified into two groups on the basis of the diameter of seminiferous tubules measured against 5/0 surgical suture (≥100 µm or <100 µm)., Results: The sperm retrieval rate (SRR) in men with a tubule diameter ≥100 µm was significantly lower than that in those with <100 µm (3.1% vs. 25.0%). The SRR from the contralateral testis in men with a tubule diameter ≥100 µm was lower than that in those with <100 µm (0% vs. 14.3%). Men with a tubule diameter ≥100 µm had a significantly larger testis and lower follicle-stimulating hormone levels than did men with <100 µm (8.1 ± 2.4 vs. 5.3±1.8 mL, 19.9 ± 9.7 vs. 25.9 ± 7.1 mIU/mL, respectively)., Conclusions: The diameter of tubules is a useful predictor for a successful SRR in men with SCOS. Intraoperative assessment of homogeneous large tubules allows some men to perform a limited (superficial) contralateral micro-TESE after no spermatozoa are initially identified.

Genetic abnormalities could account for 10% to 15% of male infertility cases, so increasing attention is being paid to gene mutations in this context. DNAH1 gene polymorphisms are highly correlated with astheno-teratozoospermia, but limited information has been reported on pathogenic variations in DNAH1 in the Chinese population. We explored 4 novel variations of the DNAH1 gene in Chinese infertile patients. Mutation screening of the DNAH1 gene was performed on 87 cases of asthenozoospermia with targeted high-throughput sequencing technology; another 200 nonobstructive azoospermia cases were further analyzed to investigate the prevalence of DNAH1 variations. The effects of the variations on protein function were further assessed by bioinformatic prediction. For carriers of DNAH1 variations, genetic counseling should be considered. Assisted reproductive technologies should be performed for these individuals and microsurgery should be considered for patients with azoospermia. DNAH1 variations were identified in 6 of 287 patients. These included 8 heterozygous variations in exons and a splicing site. Among these, 4 variations (g.52400764G>C, g.52409336C>T, g.52430999&#95;52431000del, g.52412624C>A) had already been registered in the 1000 Genomes and Exome Aggregation Consortium databases. The other 4 novel variations (g.52418050del, g.52404762T>G, g.52430536del, g.52412620del) were all predicted to be pathogenic by in silico analysis. The variations g.52418050del and g.52430999&#95;52431000del were detected in 1 patient who was more severe than another patient with the variation g.52430999&#95;52431000del. Physicians should be aware of genetic variants in male infertility patients and DNAH1 mutations should be considered in patients with asthenospermia or azoospermia.

Only a few studies evaluate the presence of spermatozoa intraoperatively. The study aimed to assess whether the heterogenicity of testicular histopathology and seminiferous tubules can predict the outcome of microdissection testicular sperm extraction (micro-TESE) in men with nonobstructive azoospermia (NOA).The study comprised a retrospective analysis of 94 patients with azoospermia who were referred from 2016 to 2017. Under optical magnification, they were classified into 2 groups based on the diameter of tubules intraoperatively, namely homogeneous tubules and heterogeneous tubules. Postoperatively, patients were divided into 2 groups of heterogeneous histopathology and homogeneous histopathology according to the 8 histopathological classification subgroups. The sperm retrieval rate was the main outcome.Testicular spermatozoa were successfully retrieved in 27 men (28%). The sperm retrieval rate in those with heterogeneous histopathology was higher than men with homogeneous histopathology (47% vs 12%; P < .001). The sperm retrieval rate of each histopathological subgroup in men who had the heterogeneous histopathology was higher, compared with the homogeneous histopathology (Sertoli cell only [SCO]: 30% vs 6%; maturation arrest [MA]: 38% vs 0%; tubular hyalinization: 42% vs 20%, respectively). Under the optical magnification, the sperm retrieval rate was significantly higher in men with heterogeneous vs homogeneous tubules (65% vs 15%, P < .001). Moreover, the sperm retrieval rate of the contralateral testicular was higher in men who had heterogeneous tubules, compared with the homogeneous tubules (25% vs 3%; P = .036).Heterogenicity of histopathology is an effective predictor in men with histopathological information available from a previous diagnostic biopsy or conventional TESE attempt preoperatively for successful sperm retrieval. Homogeneous tubules seem beneficial for some patients to perform a limited (superficial) contralateral micro-TESE after no spermatozoa were identified initially.

The present study describes a 36‑year‑old male with the 45,X/46,X,i(Yq)/46,X,idic(Yq) karyotype, who suffered from azoospermia attributed to maturation arrest of the primary spermatocyte. To the best of our knowledge, this rare karyotype has not yet been reported in the literature. The results of detailed molecular‑cytogenetic studies of isodicentric (idic)Y chromosomes and isochromosome (iso)Y, which are identified in patient with complex mosaic karyotypes, are presented. The presence of mosaicism of the three cell lines 45,X, 46,X,i(Yq) and 46,X,idic(Yq) may be a contributing factor for spermatogenic failure, in addition to the instability of iso/idic Y chromosomes to pass the spermatogenesis process. Possible mechanisms of the formation of the mosaic karyotype and karyotype‑phenotype correlations are discussed. The current study highlights that routine karyotype analysis and fluorescent in situ hybridization‑based technology are more useful in detecting mosaic chromosomal abnormality, predicting the clinical features of patients during genetic counseling and improving artificial reproductive technologies.

The outcomes and safety of intracytoplasmic sperm injection (ICSI) using testicular sperm have been controversial. We evaluated ICSI results, pregnancy outcomes, and neonatal health conditions using testicular sperm from patients with obstructive (OA) or nonobstructive (NOA) azoospermia. We further compared the ICSI outcomes after use of fresh versus cryopreserved testicular sperm from men with NOA. We included 314 men with NOA who underwent microdissection testicular sperm extraction (mTESE) and 303 with OA who underwent testicular sperm aspiration; both groups underwent ICSI. Therefore, 101 and 329 ICSI cycles were performed for mTESE and aspirated sperms, respectively. Furthermore, fresh and thawed embryos from both groups were transplanted to evaluate fertilization and pregnancy rates (NOA, 15 fresh and 123 thawed; OA, 59 fresh and 393 thawed). Finally, of the 101 ICSI cycles performed for NOA patients, 56 fresh-sperm cycles and 45 thawed-sperm cycles were performed to evaluate ICSI outcomes. Fertilization rates and two-pronuclear (2PN) fertilization rates were significantly lower in the NOA group than in the OA group. However, the 2PN cleavage rate, the high-quality embryo rate, the blastocyst formation rate, and the available blastocyst rate showed no significant intergroup differences. In addition, the pregnancy outcomes and neonatal health conditions were statistically similar. Finally, compared with thawed sperm, the fresh-sperm group had a higher 2PN fertilization rate and a higher high-quality embryo rate. However, blastocyst formation and available blastocyst rates were similar between the two groups. Patients with NOA achieved the same favorable results in embryo development, clinical pregnancy, and live birth capability as did OA patients. Neonatal conditions were not affected by type of azoospermia (NOA versus OA). For patients with NOA, fresh testicular sperm is superior to frozen-thawed testicular sperm in embryo development as evaluated at the cleavage stage, but we find no superiority evaluating at the stage of blastocyst formation. [ABSTRACT FROM AUTHOR]

Background: Non-obstructive azoospermia (NOA) affects nearly 1% of men; however, the landscape of the causative genes is largely unknown. Objective: To explore the genetic etiology which is the fundamental cause of NOA, a prospective case-control study and parental–proband trio linkage analysis were performed. Materials: A total of 133 patients with clinicopathological NOA and 343 fertile controls were recruited from a single large academic fertility center located in Northeast China; in addition, eleven trio families were available and enrolled. Results: Whole exome sequencing-based rare variant association study between the cases and controls was performed using the gene burden association testing. Linkage analysis on the trio families was also interrogated. In total, 648 genes were identified to be associated with NOA (three of which were previously reported), out of which six novel genes were found further associated based on the linkage analysis in the trio families, and involved in the meiosis-related network. Discussion and Conclusion : The six currently identified genes potentially account for a fraction (3.76%, 5 out of 133 patients) of the heritability of unidentified NOA, and combining the six novel genes and the three previously reported genes together would potentially account for an overall 6.77% (9 out of 133 patients) heritability of unidentified NOA in this study. [ABSTRACT FROM AUTHOR]