Genetic Variation of Follicle-Stimulating Hormone Action Is Associated With Age at Testicular Growth in Boys

Pubertal timing, sex hormone levels, and associations between early life adversity and accelerated development amongst 11-year-old children of parents with schizophrenia or bipolar disorder and controls: The Danish high risk and Resilience study via 11

Background

Children of parents with severe mental illness have several known risk factors for altered pubertal timing. Pubertal timing is important for children's physical and emotional development. We aimed to examine pubertal timing and associations between pubertal timing, early life adversity and child problem behavior including psychiatric diagnoses among children of parents with schizophrenia or bipolar disorder and controls.

Methods

Self-reported Tanner stage (mean age 11.9, range 10.87-12.67), sex hormone levels, home environment, placement out of home, and problem behavior including psychiatric diagnoses of children at familial high-risk (FHR) of schizophrenia (FHR-SZ), bipolar disorder (FHR-BP) and population-based controls (PBC) were assessed.

Results

A total of 465 children participated in the study (Tanner assessment N = 417, sex hormones N = 293). Assessed with self-reported Tanner, no difference in pubertal timing was found between groups (p = 0.09). Hormone levels did not differ between groups except for inhibin B (mean (SD) = 55.86 (29.13) pg/mL for FHR-SZ girls vs 84.98 (47.98) pg/mL) for PBC girls (p < 0.001)) and for follicle stimulating hormone (FSH) (mean (SD) = 5.82 (1.45) U/L for FHR-BP girls vs 4.54 (1.68) U/L for PBC girls (p < 0.001)). FHR children who were placed out of home (17 children, 3.8% of participants) had higher Tanner stages than those living at home (p < 0.001). Timing was not associated with level of problem behavior or psychiatric diagnoses.

Conclusions

FHR children did not differ from controls in pubertal timing. Early life adversity assessed as placement out of home may be associated with accelerated pubertal timing among children of parents with schizophrenia or bipolar disorder.

Prospects for FSH Treatment of Male Infertility

CONTEXT

Despite the new opportunities provided by assisted reproductive technology (ART), male infertility treatment is far from being optimized. One possibility, based on pathophysiological evidence, is to stimulate spermatogenesis with gonadotropins.

EVIDENCE ACQUISITION

We conducted a comprehensive systematic PubMed literature review, up to January 2020, of studies evaluating the genetic basis of follicle-stimulating hormone (FSH) action, the role of FSH in spermatogenesis, and the effects of its administration in male infertility. Manuscripts evaluating the role of genetic polymorphisms and FSH administration in women undergoing ART were considered whenever relevant.

EVIDENCE SYNTHESIS

FSH treatment has been successfully used in hypogonadotropic hypogonadism, but with questionable results in idiopathic male infertility. A limitation of this approach is that treatment plans for male infertility have been borrowed from hypogonadism, without daring to overstimulate, as is done in women undergoing ART. FSH effectiveness depends not only on its serum levels, but also on individual genetic variants able to determine hormonal levels, activity, and receptor response. Single-nucleotide polymorphisms in the follicle-stimulating hormone subunit beta (FSHB) and follicle-stimulating hormone receptor (FSHR) genes have been described, with some of them affecting testicular volume and sperm output. The FSHR p.N680S and the FSHB -211G>T variants could be genetic markers to predict FSH response.

CONCLUSIONS

FSH may be helpful to increase sperm production in infertile men, even if the evidence to recommend the use of FSH in this setting is weak. Placebo-controlled clinical trials, considering the FSHB-FSHR haplotype, are needed to define the most effective dosage, the best treatment length, and the criteria to select candidate responder patients.

Obesity Is Associated with Earlier Pubertal Onset in Boys

CONTEXT

Pubertal timing in boys is associated with body mass index (BMI). Studies consistently report an inverse correlation of BMI and pubertal timing within the normal BMI range. However, observations in obese boys are conflicting with different studies reporting either early or delayed pubertal onset in obese boys.

OBJECTIVE

We aimed to assess the association of male pubertal timing with age-specific BMI (zBMI) in obese boys.

DESIGN, SETTING, AND PARTICIPANTS

A total of 218 obese boys (zBMI > +2SD, with a median age at baseline of 10.8 years (range 4.2-17.0), were recruited as part of a prospective outpatient childhood obesity intervention program at Nordsjællands Hospital, Hillerød, Denmark, between 2009 and 2017. Serving as controls, we included 660 healthy boys participating in the population-based COPENHAGEN Puberty Study (-2SD < zBMI ≤ +2SD, 2006-2014). Subanalyses were performed on overweight controls (+1SD < zBMI ≤ +2SD). The clinical assessment of pubertal development by Tanner staging, including testis volume using a Prader's orchidometer, was performed by trained physicians. The timing of pubertal milestones was estimated by probit analyses.

MAIN OUTCOME MEASURES

Timing of testicular volume ≥ 4 mL, genital stage ≥ 2, and pubarche.

RESULTS

The mean (95% confidence interval [CI]) age of onset of pubertal event in obese boys was as follows: testicular volume ≥ 4 mL, 11.3 years (11.0-11.6); genital stage ≥ 2, 11.6 yrs (11.3-11.9); and pubarche, 11.9 years (11.5-12.3). Testicular volume ≥ 4 mL occurred significantly earlier in obese boys compared to controls (-2SD < zBMI ≤ +2SD) (P = 0.01). We did not observe significant differences for either the timing of pubarche nor the genital stage ≥ 2 (P = 0.06 and P = 0.94, respectively).

CONCLUSIONS

We demonstrate that testicular enlargement in obese boys occurs significantly earlier compared to a population-based normal-weight reference cohort.

Does the FSHB c.-211G>T polymorphism impact Sertoli cell number and the spermatogenic potential in infertile patients?

BACKGROUND

A genetic variant within the FSHB gene can deviate FSH action on spermatogenesis. The c.-211G>T FSHB single nucleotide polymorphism impacts FSHB transcription and biosynthesis due to interference with the LHX3 transcription factor binding. This SNP was previously shown to be strongly associated with lowered testicular volume, reduced sperm counts, and decreased FSH levels in patients carrying one or two T-alleles.

OBJECTIVE

To determine the impact of the SNP FSHB c.-211G>T on Sertoli cell (SC) number, Sertoli cell workload (SCWL) and thereby spermatogenic potential.

MATERIAL AND METHODS

Testicular biopsies of 31 azoospermic, homozygous T patients (26 non-obstructive azoospermia (NOA), and five obstructive azoospermia (OA)) were matched to patients with GG genotype. Marker proteins for SC (SOX9), spermatogonia (MAGE A4), and round spermatids (CREM) were used for semi-automatical quantification by immunofluorescence. SCWL (number of germ cells served by one SC) was determined and an unbiased clustering on the patient groups performed.

RESULTS

Quantification of SC number in NOA patients did not yield significant differences when stratified by FSHB genotype. SC numbers are also not significantly different between FSHB genotypes for the OA patient group and between NOA and OA groups. SCWL in the NOA patient cohort is significantly reduced when compared to the OA control patients; however, in neither group an effect of the genotype could be observed. The cluster analysis of the whole study cohort yielded two groups only, namely NOA and OA, and no clustering according to the FSHB genotype.

DISCUSSION AND CONCLUSION

The FSHB c.-211G>T polymorphism does not affect SC numbers or SCWL, thereby in principle maintaining the spermatogenic potential. The previously observed clinical phenotype for the FSHB genotype might therefore be caused by a hypo-stimulated spermatogenesis and not due to a decreased SC number.

Voice break in boys-temporal relations with other pubertal milestones and likely causal effects of BMI

STUDY QUESTION

How is timing of voice break related to other male pubertal milestones as well as to BMI?

SUMMARY ANSWER

We provide a comprehensive temporal analysis of male pubertal milestones, including reproductive hormone dynamics, confirm voice break as a late milestone of male puberty and report a likely causal relationship between higher BMI and earlier age at voice break in men.

WHAT IS KNOWN ALREADY

Voice break represents a late pubertal milestone and recalled age at voice break is frequently used in epidemiological studies as a measure of puberty. In contrast, clinical studies use mainly testicular enlargement and/or genital tanner stage as the marker of pubertal onset. However, neither correlation of pubertal milestones nor reproductive hormone dynamics have been assessed in detail previously. Further, although BMI and puberty timing are known to be closely linked, cause and effect between these traits are not known.

STUDY DESIGN, SIZE, DURATION

The study included a population-based mixed cross-sectional and longitudinal cohort (2006-2014, COPENHAGEN Puberty Study) of 730 healthy Danish boys. Data for 55 871 male research participants from the 23andMe study were obtained, including genome-wide single nucleotide polymorphism data and age at voice break.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We performed a detailed evaluation of pubertal milestones and reproductive hormone levels (study population 1). A Mendelian randomization (MR) approach was used to determine the likely causal link between BMI and timing of voice break (study population 2).

MAIN RESULTS AND THE ROLE OF CHANCE

Voice break occurred at mean age 13.6 (95% CI: 13.5-13.8) years. At voice break, mean (95% CI) testosterone levels, LH levels and bi-testicular volume were 10.9 (10.0-11.7) nmol/L, 2.4 (2.2-2.5) IU/L and 24 (23-25) mL, respectively. Voice break correlated moderately strongly with timing of male pubertal milestones, including testicular enlargement, gonadarche, pubarche, sweat odor, axillary hair growth and testosterone above limit of detection (r2 range: 0.43-0.61). Timing of all milestones was negatively associated with age-specific BMI (all P ≤ 0.001). MR analyses inferred likely causal effects of higher BMI on earlier voice break in males (-0.35 years/approximate SD, P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

Participation rate of the population-based cohort was 25%. Further, boys that were followed longitudinally were examined approximately every 6 months limiting the time resolution of pubertal milestones. Using adult BMI as exposure instead of prepubertal BMI in the MR analysis and the known inaccuracies of the testosterone immunoassay at low testosterone levels may be further limitations.

WIDER IMPLICATIONS OF THE FINDINGS

We provide valuable normative data on the temporal relation of male pubertal milestones. Further, the likely causal relationship between BMI and puberty timing highlights the importance of preventing obesity in childhood.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by Danish Agency for Science, Technology and Innovation (09-067 180); Danish Ministry of the Environment, CeHoS (MST-621-00 065); Capital Region of Denmark (R129-A3966); Ministry of Higher Education and Science (DFF-1331-00 113); Innovation Fund Denmark (InnovationsFonden, 14-2013-4); The International Center for Research and Research Training in Endocrine Disrupting Effects of Male Reproduction and Child Health. B.H., F.R.D., J.R.B.P. and K.K.O. are supported by the Medical Research Council (MC_UU_12015/2). The 23andMe study is supported by the National Human Genome Research Institute of the National Institutes of Health (R44HG006981). Members of the 23andMe Research Team are employees of 23andMe, Inc. and hold stock or stock options in 23andMe.

TRIAL REGISTRATION NUMBER

NCT01411527.

Constitutional delay of puberty versus congenital hypogonadotropic hypogonadism: Genetics, management and updates

Delayed puberty (DP) affects approximately 2% of adolescents. In the vast majority of patients in both sexes, it is due to constitutional delay of growth and puberty (CDGP), a self-limited condition in which puberty starts later than usual but progresses normally. However, some CDGP patients may benefit from medical intervention with low-dose sex steroids or peroral aromatase inhibitor letrozole (only for boys). Other causes of DP include permanent hypogonadotropic hypogonadism, functional hypogonadotropic hypogonadism (due to chronic diseases and conditions), and gonadal failure. In this review we discuss these themes along with the latest achievements in the field of puberty research, and include a brief synopsis on the differential diagnosis and management of patients with CDGP and congenital hypogonadotropic hypogonadism.

FSHB -211 G>T Polymorphism as Predictor for TESE Success in Patients With Unexplained Azoospermia

CONTEXT

Testicular sperm extraction (TESE) followed by assisted reproductive techniques often remains the only therapeutic option for men with azoospermia due to spermatogenic failure. Reproductive parameters, such as gonadotropin levels and testicular volume or histopathology, contribute to the prediction of sperm retrieval rate (SRR) in TESE. However, there is an eminent lack of noninvasive predictive factors for TESE outcome.

OBJECTIVE

To clarify the impact of three common genetic variants affecting FSH and its cognate receptor on testicular histopathology patterns and SRR in TESE.

DESIGN

We evaluated the association of the single-nucleotide polymorphisms (SNP) FSHB -211G>T (rs10835638), FSHR -29G>A (rs1394205), and FSHR c.2039A>G (rs6166) with testicular histopathology and SRR in patients with azoospermia.

SETTING

Tertiary referral center for andrology.

PATIENTS OR OTHER PARTICIPANTS

Men (n = 1075) with azoospermia who underwent TESE (grouped by clinical pathologies).

INTERVENTION(S)

All participants underwent TESE.

MAIN OUTCOME MEASURE(S)

Testicular histopathology, SRR, and reproductive hormone levels.

RESULTS

FSHB -211G>T was significantly associated with reduced chances of sperm retrieval in patients with unexplained azoospermia. Indicating an additional mechanism, the association of the SNP with SSR could not be solely attributed to decreased FSH levels.

CONCLUSION

A common genetic factor was significantly associated with SRR in TESE. In perspective, a calculator or score including the noninvasive parameters FSH level, testicular volume, and FSHB haplotype should be considered to estimate the chances for sperm retrieval in men with azoospermia.

Pharmacogenetics of FSH Action in the Male

Male infertility is a major contributor to couple infertility, however in most cases it remains "idiopathic" and putative treatment regimens are lacking. This leads to a scenario in which intra-cytoplasmic spermatozoa injection (ICSI) is widely used in idiopathic male infertility, though the treatment burden is high for the couple and it entails considerable costs and risks. Given the crucial role of the Follicle-stimulating hormone (FSH) for spermatogenesis, FSH has been used empirically to improve semen parameters, but the response to FSH varied strongly among treated infertile men. Single nucleotide polymorphisms (SNPs) within FSH ligand/receptor genes (FSHB/FSHR), significantly influencing reproductive parameters in men, represent promising candidates to serve as pharmacogenetic markers to improve prediction of response to FSH. Consequently, several FSH-based pharmacogenetic studies have been conducted within the last years with unfortunately wide divergence concerning selection criteria, treatment and primary endpoints. In this review we therefore outline the current knowledge on single nucleotide polymorphisms (SNPs) in the FSH and FSH receptor genes and their putative functional effects. We compile and critically assess the previously performed pharmacogenetic studies in the male and propose a putative strategy that might allow identifying patients who could benefit from FSH treatment.

Genetics of pubertal timing

PURPOSE OF REVIEW

To summarize advances in the genetics underlying variation in normal pubertal timing, precocious puberty, and delayed puberty, and to discuss mechanisms by which genes may regulate pubertal timing.

RECENT FINDINGS

Genome-wide association studies have identified hundreds of loci that affect pubertal timing in the general population in both sexes and across ethnic groups. Single genes have been implicated in both precocious and delayed puberty. Potential mechanisms for how these genetic loci influence pubertal timing may include effects on the development and function of the GnRH neuronal network and the responsiveness of end-organs.

SUMMARY

There has been significant progress in identifying genetic loci that affect normal pubertal timing, and the first single-gene causes of precocious and delayed puberty are being described. How these genes influence pubertal timing remains to be determined.

Deletion in the uridine diphosphate glucuronyltransferase 2B17 gene is associated with delayed pubarche in healthy boys

OBJECTIVE

Only a few genetic loci are known to be associated with male pubertal events. The ability of excreting testosterone (T) and other steroids in the urine depends on sulfation and glucuronidation. One of several essential glucuronidases is encoded by the UGT2B17 gene. In a preliminary report, we found that homozygous deletion of UGT2B17 in boys was associated with lower urinary excretion of T. We hypothesized that boys with a lower glucuronidation capacity may have altered androgen action and excretion affecting pubarche, as this represents a T-dependent event.

DESIGN, PARTICIPANTS AND MEASURES

668 healthy boys (cross-sectional) aged 6.1-21.9 years (COPENHAGEN puberty study conducted from 2005 to 2006) were included. 65 of the boys where followed longitudinally every 6 months. Participants were genotyped for UGT2B17 copy number variation (CNV). Clinical pubertal staging including orchidometry, anthropometry and serum reproductive hormone levels.

RESULTS

59 of the 668 boys (8.8%) presented with a homozygous deletion of UGT2B17 (del/del). These boys experienced pubarche at a mean age of 12.73 years (12.00-13.46) vs 12.40 years (12.11-12.68) in boys heterozygous for deletion of UGT2B17 (del/ins) vs 12.06 years (11.79-12.33) in boys with the wild-type genotype (ins/ins) (P = 0.029, corrected for BMI z-score). The effect accounted for 0.34 years delay per allele (95% CI: 0.03-0.64). A comparable trend was observed for onset of testicular enlargement >3 mL but did not reach significance.

CONCLUSION

CNV of UGT2B17 is a factor contributing to the timing of male pubarche.

Differential Impact of Genetic Loci on Age at Thelarche and Menarche in Healthy Girls

CONTEXT

Recent genetic studies have identified genetic variants associated with age at pubertal onset. Whereas genome-wide association studies reported associations of several hundred genetic variants with timing of self-reported age at menarche, a recent clinical study focused on genetic variation affecting follicle-stimulating hormone action and clinically determined age at thelarche. The observations appear to be incongruent, as effect sizes varied substantially among the studies. Alternatively, this may point to a differential impact of specific genetic loci on distinct pubertal events.

OBJECTIVE

To investigate whether top-candidate genetic variants exhibit a different impact on timing of thelarche vs menarche, respectively.

DESIGN

Cross-sectional and longitudinal study of healthy girls.

SETTING

Population-based study in the Copenhagen area.

PATIENTS OR OTHER PARTICIPANTS

Girls (1478) were followed through puberty and genotyped for FSHB c.-211G>T (rs10835638), FSHR c.-29G>A (rs1394205), FSHR c.2039A>G (rs6116), LIN28B (rs7759938), INHA (rs4141153), MKRN3 (rs12148769), TMEM38B (rs10453225), and ZNF483 (rs10980921).

MAIN OUTCOME MEASURES

Clinical pubertal staging and anthropometric data.

RESULTS

We observed an association of LIN28B (rs7759938) with age at thelarche (P < 0.001, effect size: 0.27 year, 95% confidence interval: 0.12 to 0.42) and age at menarche (P = 0.005, 0.17 year, 0.05 to 0.29). FSHB c.-211G>T (rs10835638) and FSHR c.-29G>A (rs1394205) minor allele count was associated with age at thelarche (P = 0.004, 0.19 year, 0.06 to 0.31) but not with age at menarche (P = 0.97; all adjusted for body mass index z scores).

CONCLUSION

Our results indicate a differential impact of specific genetic loci on age at thelarche and menarche in healthy girls.

Polymorphisms in JMJD1C are associated with pubertal onset in boys and reproductive function in men

JMJD1C, a member of the Jumonji-domain containing histone demethylases protein family, has been associated with levels of sex-hormone binding globulin (SHBG) and testosterone in men, and knock-out rodent models show age-dependent infertility. The objective of this study was to investigate whether single nucleotide polymorphisms (SNPs) nearby JMJD1C are associated with pubertal onset in boys and with male reproduction. 671 peri-pubertal boys, 1,027 young men, 315 fertile men, and 252 infertile men were genotyped for two JMJD1C SNPs (rs7910927 and rs10822184). rs7910927 and rs10822184 showed high linkage. Boys with the rs7910927 TT genotype entered puberty 3.6 months earlier than their peers (p = 2.5 × 10⁻²). In young men, the number of T alleles was associated with decreased levels of SHBG, follicle-stimulating hormone (FSH), testosterone, and testosterone x luteinizing hormone, as well as increased levels of Inhibin B, Inhibin B/FSH ratio, and testis size. No significant associations with semen parameters were observed and the genotype distribution was comparable among fertile and infertile men. In conclusion, genetic variation in the vicinity of JMJD1C had a surprisingly large impact on the age at pubertal onset in boys as well as levels of reproductive hormones and testis size in men, emphasizing the relationship between JMJD1C and reproductive functions.