Androgens act through the androgen receptor (AR), which regulates nearly a thousand genes. The human AR gene contains polymorphic repeats, including (CAG)n and (GGN)n, which affect AR transactivation. This study investigated their independent and combined effects on reproductive and general health. The study included 866 patients with male factor infertility (mean age: 32.8 years, and standard deviation: 6.8 years). Standard protocols were followed for semen analysis, phenotyping, and laboratory data collection. Repeat numbers of (CAG)n and (GGN)n polymorphisms were detected simultaneously using an established genotyping assay. Significantly lower sperm counts were observed in carriers of the AR gene with ≥24 compared to ≤22 GGN repeats (median: 13.5 × 106 vs 18.2 × 106 per ejaculate, P < 0.01). The meta-analysis with the Baltic young men cohort confirmed this association (n = 1843; linear regression: β = -0.38 × 106 [95% confidence interval, 95% CI: -0.75 × 106 to -0.01 × 106] per ejaculate, P = 0.044). The effect was further enhanced by long AR (CAG)n tract (≥25 repeats). The lowest sperm counts (median: 13.6 × 106 per ejaculate) and concentrations (3.5 × 106 ml-1) were detected in carriers of the AR haplotype combining ≥24 GGN and ≥25 CAG repeats (6.8% of patients). For AR (CAG)n repeats, a positive association was observed only with body mass index (BMI; P = 0.02). Neither AR repeat stretch affected semen volume, serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, glucose, lipids, uric acid, or C-reactive protein (CRP) levels. In conclusion, an increased AR (GGN)n repeat number exerts a pronounced negative modulatory effect on sperm parameters. To date, only a limited number of common genetic variants have been reported to be associated with quantitative sperm parameters.

STUDY QUESTION:What is the impact of undiagnosed microdeletion and microduplication syndromes (MMS) for men with idiopathic low sperm count? SUMMARY ANSWER:Among idiopathic male infertility, ∼2% of cases harbour known disease-causing microdeletions and duplications linked to clinically well-established syndromes, representing ∼2.5-fold higher prevalence than in the general population. WHAT IS KNOWN ALREADY:While infertility affects up to 10% of men, a substantial proportion of cases remain with no identifiable underlying cause. Recurrent submicroscopic losses or gains cause MMS, some of which also impact reproductive phenotypes, including cryptorchidism and reduced fertility. STUDY DESIGN, SIZE, DURATION:This retrospective study investigated the proportion of undiagnosed MMS among idiopathic male infertility cases. Patients with unexplained low total sperm counts (TSC; defined as ≤39 million sperm per ejaculate) were recruited to the ESTonian ANDrology (ESTAND) cohort at the Andrology Clinic of Tartu University Hospital (AC-TUH) in Estonia. A total of 504 men were included in the analysis, and the study capitalized on available whole-exome sequencing (WES) data to explore large (>500 kb) chromosomal deletions and duplications. PARTICIPANTS/MATERIALS, SETTING, METHODS:Copy number variant (CNV) calling was executed on the WES dataset, followed by a stringent, custom-developed filtering pipeline that retained only high-confidence CNVs larger than 500 kb. Candidate CNVs were validated by chromosomal microarray analysis (CMA) or whole-genome sequencing (WGS). Prevalence of identified MMS-linked deletions and duplications in the ESTAND cohort was compared to general population literature data. MAIN RESULTS AND THE ROLE OF CHANCE:A total of nine patients (1.8%) carried losses and gains linked to clinically well-characterized MMS-recurrent microdeletions at 16p11.2 (two cases), 2q13-14.1, and 15q13.2-13.3, and microduplications at 22q11.21 (three cases), 16p11.2, and 8p23.1. The total burden of MMS among infertile men was ∼2.5-fold higher compared to the general population (P = 0.01, χ2 test). Cryptorchidism was a novel shared feature among all individuals with 16p11.2 rearrangements, suggesting a potential role in disrupting testicular development. Three subjects with MMS-linked microduplications, but none with a microdeletion, had achieved biological fatherhood. An oligozoospermia case (TSC 1.92 × 106/ej.) with 16p11.2 duplication had a naturally conceived child in youthhood. For two men carrying 22q11.21 duplication (TSC 0 and 4.2 × 106/ej., respectively), implementation of ARTs-ICSI with or without preceding testicular sperm aspiration-resulted in successful conception and childbirth. Evidence for a plausible link to male gonadal development and function has been reported for MAZ and KCTD13 at 16p11.2, and LZTR1 at 22q11.21. As an additional finding, a novel ∼3.8 Mb microduplication at 3p25.1 was identified in an oligozoospermia patient and his azoospermic son, conceived naturally at the age of 28 years. This region encompasses a triplosensitive gene, NR2C2, linked to affected meiosis and oligozoospermia in mouse models. LIMITATIONS, REASONS FOR CAUTION:WES may not detect all structural variations, such as inversions or balanced translocations. As some MMS CNVs were only identified in singleton cases (8p23.1 duplication, 2q13-14.1 and 15q13.2-13.3 deletions), the link to male infertility could not be clarified. Further data are needed about the novel large 3p25.1 microduplication to understand its effect on spermatogenesis. WIDER IMPLICATIONS OF THE FINDINGS:The yield of identified MMS in idiopathic cases with low sperm counts (∼2%) was close to the carriership of Y-chromosome microdeletions, tested in routine infertility workup. Early identification of MMS can inform genetic counselling regarding congenital health risks to the patient and future offspring and options for decision-making in ART. STUDY FUNDING/COMPETING INTEREST(S):This study was supported by the Estonian Research Council (Grant number PRG1021 to M.L.). The authors declare that they have no conflict of interest in relation to the data in this paper. TRIAL REGISTRATION NUMBER:N/A.

RASopathies are syndromes caused by congenital defects in the Ras/mitogen-activated protein kinase (MAPK) pathway genes, with a population prevalence of 1 in 1,000. Patients are typically identified in childhood based on diverse characteristic features, including cryptorchidism (CR) in >50% of affected men. As CR predisposes to spermatogenic failure (SPGF; total sperm count per ejaculate 0–39 million), we hypothesized that men seeking infertility management include cases with undiagnosed RASopathies. Likely pathogenic or pathogenic (LP/P) variants in 22 RASopathy-linked genes were screened in 521 idiopathic SPGF patients (including 155 CR cases) and 323 normozoospermic controls using exome sequencing. All 844 men were recruited to the ESTonian ANDrology (ESTAND) cohort and underwent identical andrological phenotyping. RASopathy-specific variant interpretation guidelines were used for pathogenicity assessment. LP/P variants were identified in PTPN11 (two), SOS1 (three), SOS2 (one), LZTR1 (one), SPRED1 (one), NF1 (one), and MAP2K1 (one). The findings affected six of 155 cases with CR and SPGF, three of 366 men with SPGF only, and one (of 323) normozoospermic subfertile man. The subgroup “CR and SPGF” had over 13-fold enrichment of findings compared to controls (3.9% vs. 0.3%; Fisher’s exact test, p = 5.5 × 10−3). All ESTAND subjects with LP/P variants in the Ras/MAPK pathway genes presented congenital genitourinary anomalies, skeletal and joint conditions, and other RASopathy-linked health concerns. Rare forms of malignancies (schwannomatosis and pancreatic and testicular cancer) were reported on four occasions. The Genetics of Male Infertility Initiative (GEMINI) cohort (1,416 SPGF cases and 317 fertile men) was used to validate the outcome. LP/P variants in PTPN11 (three), LZTR1 (three), and MRAS (one) were identified in six SPGF cases (including 4/31 GEMINI cases with CR) and one normozoospermic man. Undiagnosed RASopathies were detected in total for 17 ESTAND and GEMINI subjects, 15 SPGF patients (10 with CR), and two fertile men. Affected RASopathy genes showed high expression in spermatogenic and testicular somatic cells. In conclusion, congenital defects in the Ras/MAPK pathway genes represent a new congenital etiology of syndromic male infertility. Undiagnosed RASopathies were especially enriched among patients with a history of cryptorchidism. Given the relationship between RASopathies and other conditions, infertile men found to have this molecular diagnosis should be evaluated for known RASopathy-linked health concerns, including specific rare malignancies.

Infertility, affecting similar to 10% of men, is predominantly caused by primary spermatogenic failure (SPGF). We screened likely pathogenic and pathogenic (LP/P) variants in 638 candidate genes for male infertility in 521 individuals presenting idiopathic SPGF and 323 normozoospermic men in the ESTAND cohort. Molecular diagnosis was reached for 64 men with SPGF (12%), with findings in 39 genes (6%). The yield did not differ significantly between the subgroups with azoospermia (20/185, 11%), oligozoospermia (18/181, 10%), and primary cryptorchidism with SPGF (26/155, 17%). Notably, 19 of 64 LP/P variants (30%) identified in 28 subjects represented recurrent findings in this study and/or with other male infertility cohorts. NR5A1 was the most frequently affected gene, with seven LP/P variants in six SPGF-affected men and two normozoospermic men. The link to SPGF was validated for recently proposed candidate genes ACTRT1, ASZ1, GLUD2, GREB1L, LEO1, RBM5, ROS1, and TGIF2LY. Heterozygous truncating variants in BNC1, reported in female infertility, emerged as plausible causes of severe oligozoospermia. Data suggested that several infertile men may present congenital conditions with less pronounced or pleiotropic phenotypes affecting the development and function of the reproductive system. Genes regulating the hypothalamic-pituitary-gonadal axis were affected in >30% of subjects with LP/P variants. Six individuals had more than one LP/P variant, including five with two findings from the gene panel. A 4-fold increased prevalence of cancer was observed in men with genetic infertility compared to the general male population (8% vs. 2%; p = 4.4 x 10(-3)). Expanding genetic testing in andrology will contribute to the multidisciplinary management of SPGF.

Data on the clinical validity of DNA copy number variants (CNVs) in spermatogenic failure (SPGF) is limited. This study analyzed the genome-wide CNV profile in 215 men with idiopathic SPGF and 62 normozoospermic fertile men, recruited at the Andrology Clinic, Tartu University Hospital, Estonia. A two-fold higher representation of > 1 Mb CNVs was observed in men with SPGF (13%, n = 28) compared to controls (6.5%, n = 4). Seven patients with SPGF were identified as carriers of microdeletions (1q21.1; 2.4 Mb) or microduplications (3p26.3, 1.1 Mb; 7p22.3-p22.2, 1.56 Mb; 10q11.22, 1.42 Mb, three cases; Xp22.33; 2.3 Mb) linked to severe congenital conditions. Large autosomal CNV carriers had oligozoospermia, reduced or low-normal bitesticular volume (22–28 ml). The 7p22.3-p22.2 microduplication carrier presented mild intellectual disability, neuropsychiatric problems, and short stature. The Xp22.33 duplication at the PAR1/non-PAR boundary, previously linked to uterine agenesis, was detected in a patient with non-obstructive azoospermia. A novel recurrent intragenic deletion in testis-specific LRRC69 was significantly overrepresented in patients with SPGF compared to the general population (3.3% vs . 0.85%; χ 2 test, OR = 3.9 [95% CI 1.8–8.4], P = 0.0001). Assessment of clinically valid CNVs in patients with SPGF will improve their management and counselling for general and reproductive health, including risk of miscarriage and congenital disorders in future offspring.

BACKGROUND:So far, male genital tract color-Doppler ultrasound (MGT-CDUS) was not standardized. Recently, the European Academy of Andrology (EAA) published the results of a multicenter study assessing the CDUS characteristics of healthy-fertile men (HFM) to obtain normative parameters.OBJECTIVES:To report the EAA US study (i) standard operating procedures (SOPs) for assessing MGT-CDUS, (ii) main MGT-CDUS normative parameters, and (iii) compare the EAA and previously published "normal" CDUS values.METHODS:A cohort of 248 HFM (35.3 ± 5.9 years) was studied, evaluating MGT-CDUS before and after ejaculation following SOPs.RESULTS:SOPs for MGT-CDUS assessment are summarized here. All subjects underwent scrotal CDUS and 188 men underwent transrectal ultrasound before and after ejaculation. The main CDUS reference ranges and characteristics of the HFM-MGT are reported here. The mean testicular volume was ∼17 mL. The lower limit for right and left testis was 12 and 11 mL, defining testicular hypotrophy. The upper limit for epididymal head, body, tail, and vas deferens was 11.5, 5, 6, and 4.5 mm, respectively. Testicular and epididymal arterial reference ranges are reported. The EAA varicocoele classification is reported. CDUS-varicocoele was detected in ∼37% of men. Prostate mean volume was ∼25 mL, while lower and upper limits were 15 and 35 mL, defining hypotrophy and enlargement, respectively. Prostate arterial reference ranges are reported. Prostate calcifications and inhomogeneity were frequent; midline prostatic cysts were rare and small. Ejaculatory duct abnormalities were absent. The upper limit for periprostatic venous plexus was 4.5 mm. Lower and upper limits of seminal vesicles (SV) anterior-posterior diameter were 6 and 16 mm, defining hypotrophy or dilation, respectively. Seminal vesicle volume and ejection fraction reference ranges are reported. SV-US abnormalities were rare. Deferential ampullas upper limit was 6 mm. A discussion on the EAA and previously published "normal" CDUS values is reported here.CONCLUSIONS:The EAA findings will help in reproductive and general male health management.

Scrotal color Doppler ultrasound (CDUS) still suffers from lack of standardization. Hence, the European Academy of Andrology (EAA) has promoted a multicenter study to assess the CDUS characteristics of healthy fertile men (HFM) to obtain normative parameters.

The impact of sexually transmitted infections (STI) on male fertility is controversial. Aims: To investigate the prevalence of urethritis-associated STIs (chlamydia, gonorrhoeae, Mycoplasma genitalium, trichomoniasis) among infertile males; to analyze the effect of STIs on semen parameters and blood PSA. Case-control study. Study group (n = 2000): males with fertility problems or desire for fertility check. Control group (n = 248): male partners of pregnant women. Analyses: polymerase chain reaction for STI, seminal interleukin 6 (IL-6), semen and fractionated urine, blood analyses (PSA, reproductive hormones). The prevalence of M. genitalium and chlamydia in the study group was 1.1% and 1.2%, respectively. The prevalence of chlamydia in the control group was 1.6%, while there were no M. genitalium cases. No cases with gonorrhoeae or trichomoniasis or combined infections were observed in neither group. There was a higher seminal concentration of neutrophils and IL-6 among M. genitalium positives compared with STI negatives. There was a trend toward a lower total count of spermatozoa and progressive motility among STI positives. No impact of STIs on PSA was found. The prevalence of STIs among infertile males is low. M. genitalium is associated with seminal inflammation. The impact of STIs on semen parameters deserves further investigations.

Male infertility is a prevalent condition, affecting 5–10% of men. So far, few genetic factors have been described as contributors to spermatogenic failure. Here, we report the first re-sequencing study of the Y-chromosomal Azoospermia Factor c ( AZFc ) region, combined with gene dosage analysis of the multicopy DAZ, BPY2 , and CDY genes and Y-haplogroup determination. In analysing 2324 Estonian men, we uncovered a novel structural variant as a high-penetrance risk factor for male infertility. The Y lineage R1a1-M458, reported at >20% frequency in several European populations, carries a fixed ~1.6 Mb r2/r3 inversion, destabilizing the AZFc region and predisposing to large recurrent microdeletions. Such complex rearrangements were significantly enriched among severe oligozoospermia cases. The carrier vs non-carrier risk for spermatogenic failure was increased 8.6-fold (p=6.0×10 −4 ). This finding contributes to improved molecular diagnostics and clinical management of infertility. Carrier identification at young age will facilitate timely counselling and reproductive decision-making.

BACKGROUND:Infertility affects 7%-12% of men, and its etiology is unknown in half of cases. To fill this gap, use of the male genital tract color-Doppler ultrasound (MGT-CDUS) has progressively expanded. However, MGT-CDUS still suffers from lack of standardization. Hence, the European Academy of Andrology (EAA) has promoted a multicenter study ("EAA ultrasound study") to assess MGT-CDUS characteristics of healthy, fertile men to obtain normative parameters.OBJECTIVES:To report (a) the development and methodology of the "EAA ultrasound study," (b) the clinical characteristics of the cohort of healthy, fertile men, and (c) the correlations of both fertility history and seminal features with clinical parameters.METHODS:A cohort of 248 healthy, fertile men (35.3 ± 5.9 years) was studied. All subjects were asked to undergo, within the same day, clinical, biochemical, and seminal evaluation and MGT-CDUS before and after ejaculation.RESULTS:The clinical, seminal, and biochemical characteristics of the cohort have been reported here. The seminal characteristics were consistent with those reported by the WHO (2010) for the 50th and 5th centiles for fertile men. Normozoospermia was observed in 79.6% of men, while normal sperm vitality was present in almost the entire sample. Time to pregnancy (TTP) was 3.0[1.0-6.0] months. TTP was negatively correlated with sperm vitality (Adj.r =-.310, P = .011), but not with other seminal, clinical, or biochemical parameters. Sperm vitality and normal morphology were positively associated with fT3 and fT4 levels, respectively (Adj.r = .244, P < .05 and Adj.r = .232, P = .002). Sperm concentration and total count were negatively associated with FSH levels and positively, along with progressive motility, with mean testis volume (TV). Mean TV was 20.4 ± 4.0 mL, and the lower reference values for right and left testes were 15.0 and 14.0 mL. Mean TV was negatively associated with gonadotropin levels and pulse pressure. Varicocoele was found in 33% of men.CONCLUSIONS:The cohort studied confirms the WHO data for all semen parameters and represents a reference with which to assess MGT-CDUS normative parameters.

Human RBMY1 genes are located in four variable-sized clusters on the Y chromosome, expressed in male germ cells and possibly associated with sperm motility. We have re-investigated the mutational background and evolutionary history of the RBMY1 copy number distribution in worldwide samples and its relevance to sperm parameters in an Estonian cohort of idiopathic male factor infertility subjects. We estimated approximate RBMY1 copy numbers in 1218 1000 Genomes Project phase 3 males from sequencing read-depth, then chose 14 for valid ation by multicolour fibre-FISH. These fibre-FISH samples provided accurate calibration standards for the entire panel and led to detailed insights into population variation and mutational mechanisms. RBMY1 copy number worldwide ranged from 3 to 13 with a mode of 8. The two larger proximal clusters were the most variable, and additional duplications, deletions and inversions were detected. Placing the copy number estimates onto the published Y-SNP-based phylogeny of the same samples suggested a minimum of 562 mutational changes, translating to a mutation rate of 2.20 × 10-3 (95% CI 1.94 × 10-3 to 2.48 × 10-3) per father-to-son Y-transmission, higher than many short tandem repeat (Y-STRs), and showed no evidence for selection for increased or decreased copy number, but possible copy number stabilizing selection. An analysis of RBMY1 copy numbers among 376 infertility subjects failed to replicate a previously reported association with sperm motility and showed no significant effect on sperm count and concentration, serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone levels or testicular and semen volume. These results provide the first in-depth insights into the structural rearrangements underlying RBMY1 copy number variation across diverse human lineages.

PurposeThe purpose of this study was to develop a feasible approach for single sperm isolation and chromosome analysis by next-generation sequencing (NGS).MethodsSingle sperm cells were isolated from semen samples of normozoospermic male and an infertile reciprocal translocation (RcT) carrier with the 46,XY,t(7;13)(p12;q12.1) karyotype using the optimized fluorescence-activated cell sorting (FACS) technique. Genome profiling was performed using NGS.ResultsFollowing whole-genome amplification, NGS,and quality control, the final chromosome analysis was performed on 31 and 6 single cell samples derived from the RcT carrier and normozoospermic male, respectively. All sperm cells from normozoospermic male showed a normal haploid 23-chromosome profile. For the RcT carrier, the sequencing data revealed that 64.5% of sperm cells harbored different variants of chromosome aberrations, involving deletion of 7p or 7q, duplication of 7p, and duplication of 13q, which is concordant with the expected chromosome segregation patterns observed in balanced translocation carriers. In one sample, a duplication of 9q was also detected.ConclusionsWe optimized FACS protocol for simple and efficient isolation of single human sperm cells that subsequently enabled a successful genome-wide chromosome profiling and identification of segmental aneuploidies from these individual cells, following NGS analysis. This approach may be useful for analyzing semen samples of infertile men or chromosomal aberration carriers to facilitate the reproductive risk assessment.

The EAA ultrasound project was aimed at investigating the colour-Doppler ultrasound (CDUS) features of the male genital tract (MGT) in healthy, fertile men, to obtain "normative" parameters for both scrotal and transrectal CDUS.The project was developed in Florence (practical investigator meeting) and during the Berlin ECA Congress (protocol discussion) in 2012.The characteristics of the study are

Context: Testosterone (T) is a central androgenic hormone, and sex hormone-binding globulin (SHBG) is the major determinant of its bioactivity. There are no acknowledged genetic variants with clear-cut clinical implications, modulating T levels in men. Objective: To confirm genetic associations of top loci (SHBG, GCKR, SLCO1B1, and JMJD1C) from genome-wide association (GWA) studies for serum SHBG and T. Design, Patients: Groups differing in general and reproductive parameters: young men (n = 540; 19.3 ± 1.8 years), severe idiopathic male infertility patients (n = 641; 31.6 ± 6.0 years), and male partners of pregnant women (n = 324; 31.9 ± 6.6 years). All patients were recruited at the Andrology Centre, Tartu University Hospital, Estonia. Main Outcome Measure(s): Genetic associations with reproductive hormones, testicular and sperm parameters (linear regression, additive model); intergroup allele/genotype distribution comparisons. Results: Associations with serum SHBG levels were robust for SHBG −68 G>A [rs1799941; meta-analysis: P = 3.7 × 10−14; allelic effect (standard error) = 4.67 (0.62) nmol/L], SHBG +1091 C>T [rs727428; P = 7.3 × 10−11; −3.74 (0.57)], SHBG Pro185Leu [rs6258; P = 1.2 × 10−4, −12.2 (3.17)], and GCKR Pro446Leu [rs1260326; P = 1.5 × 10−4; −2.2 (0.59)]. Measured T concentrations correlated with genetically modulated levels of SHBG (r = 0.48 to 0.74, P < 0.0001), guaranteeing stable availability of free T. Among infertile men, SHBG Pro185Leu substitution showed additional downstream effect on luteinizing hormone [P = 5.1 × 10−5; −1.66 (0.57) IU/L] and follicle-stimulating hormone [P = 3.4 × 10−3; −2.48 (1.23) IU/L]. No associations with male reproductive parameters were detected for SHBG Asp327Asn (rs6259), SLCO1B1 Val174Ala (rs4149056), and JMJD1C intronic variant rs7910927. Conclusions: Claims were replicated and additional associations were detected for four of seven tested GWAS top loci. Perspective clinical investigations of these variants are hypotestosteronemia among aging men and pharmacogenetics of hormone replacement therapy.

Markimisvaarne osa inimestest jatkab seksuaalelu elamist vanemas eas ning ajas on see osakaal suurenenud. Seksuaalelu noustamise korral on hea teada pohjalikumalt seksuaalelu moistet, laheneda sellele avatult ja mittedualistlikult (erapooletult, kuid hoolivalt), et inimesi ja nende probleeme kuulata eelarvamustevabalt. Oluline on anda noustamisel olulisimat – luba olla seksuaalne olend – ning seejarel noustada patsienti professionaalsest padevusest lahtudes. Koos seksuaalmeditsiini arenguga on tekkinud mitmeid patsientide aitamise voimalusi, kuid parim on siiski teha seda eri valdkondade koostoo kaudu. Nii nagu seksuaalelu elamist, tuleks erinevas vanuses aktsepteerida ka seksuaalelu mitteelamist, arutledes, mis inimesele (partnersuhtele) on tema seisukohalt parim. Laiema seksuaalsuse definitsiooni kohaselt holmab seksuaalsus pohivajadust puudutuse, laheduse ja inimliku kiindumuse jarele ning seda vajab valdav osa inimesi kogu elu jooksul. Eesti Arst 2015; 94(10):624–627

Follicle-Stimulating Hormone Receptor (FSHR) -29G/A polymorphism (rs1394205) was reported to modulate gene expression and reproductive parameters in women, but data in men is limited. We aimed to bring evidence to the effect of FSHR -29G/A variants in men. In Baltic young male cohort (n = 982; Estonians, Latvians, Lithuanians; aged 20.2 ± 2.0 years), the FSHR -29 A-allele was significantly associated with higher serum FSH (linear regression: effect 0.27 IU/L; P = 0.0019, resistant to Bonferroni correction for multiple testing) and showed a non-significant trend for association with higher LH (0.19 IU/L) and total testosterone (0.93 nmol/L), but reduced Inhibin B (-7.84 pg/mL) and total testes volume (effect -1.00 mL). Next, we extended the study and tested the effect of FSHR gene haplotypes determined by the allelic combination of FSHR -29G/A and a well-studied variant c.2039 A/G (Asn680Ser, exon 10). Among the FSHR -29A/2039G haplotype carriers (A-Ser; haplotype-based linear regression), this genetic effect was enhanced for FSH (effect 0.40 IU/L), Inhibin B (-16.57 pg/mL) and total testes volume (-2.34 mL). Finally, we estimated the total contribution of three known FSH-action modulating SNPs (FSHB -211G/T; FSHR -29G/A, c.2039 A/G) to phenotypic variance in reproductive parameters among young men. The major FSH-action modulating SNPs explained together 2.3%, 1.4%, 1.0 and 1.1% of the measured variance in serum FSH, Inhibin B, testosterone and total testes volume, respectively. In contrast to the young male cohort, neither FSHR -29G/A nor FSHR haplotypes appeared to systematically modulate the reproductive physiology of oligozoospermic idiopathic infertile patients (n = 641, Estonians; aged 31.5 ± 6.0 years). In summary, this is the first study showing the significant effect of FSHR -29G/A on male serum FSH level. To account for the genetic effect of known common polymorphisms modulating FSH-action, we suggest haplotype-based analysis of FSHR SNPs (FSHR -29G/A, c.2039 A/G) in combination with FSHB -211G/T testing.

Follicle-stimulating hormone (FSH) is crucial for male fertility and it exerts its effects via a gonad-specific receptor (FSHR). In the present study, the common G-29A, A919G, and A2039G polymorphisms in the FSHR gene were analysed in 150 (36 non-obstructive azoospermia and 114 individuals with oligozoospermia) patients and 208 normozoospermic men. The results showed that the FSHR polymorphisms were not associated with either azoo- or oligozoospermia as the distributions of alleles, genotypes, and haplotypes among patients and controls were similar. Amongst normozoospermic men, those carrying at least one minor A allele (GA and AA genotypes) of the G-29A polymorphism had a smaller mean testicular volume compared to men with GG homozygosity (25.8 ml vs. 27.4 ml, respectively; P=0.013). In a subsequent meta-analysis combining our data with previous studies, the G-29-A919-A2039 haplotype was shown to be more prevalent in normozoospermic men than in azoospermic patients (38.4% vs. 33.9%, respectively; χ2test, P=0.045), indicating that this haplotype may be a protective factor against male sterility. In conclusion, we suggest that FSHR haplotypes are not considerable risk factors for spermatogenic failure. The protective nature of G-29-A919-A2039 haplotype cannot be concluded without additional studies.