Annette Mouritsen, Alexander Siegfried Busch, Lise Aksglaede, Ewa Rajpert-De Meyts and Anders Juul
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.
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.
CNV of UGT2B17 is a factor contributing to the timing of male pubarche.
Iben Katinka Greiber, Casper P Hagen, Alexander Siegfried Busch, Mikkel Grunnet Mieritz, Lise Aksglæde, Katharina Main, Kristian Almstrup and Anders Juul
Fetal anti-Müllerian hormone (AMH) is responsible for normal male sexual differentiation, and circulating AMH is used as a marker of testicular tissue in newborns with disorders of sex development. Little is known about the mechanism of action in postnatal life. A recent genome wide association study (GWAS) reported genetic variation of AMH affecting AMH levels in young men. This study investigated the effect of genetic variation of AMH and AMH type II receptor (AMHR2) (AMHrs10407022 T>G and AMHR2rs11170547 C>T) on circulating reproductive hormone levels and pubertal onset in boys and girls.
Design and methods
This study is a combined longitudinal and cross-sectional study in healthy Danish boys and girls from the general population. We included 658 boys aged 5.8–19.8 years and 320 girls aged 5.6–16.5 years. The main outcome measures were genotyping of AMH and AMHR2, pubertal staging and serum levels of reproductive hormones.
AMHrs10407022T>G was associated with higher serum levels of AMH in prepubertal boys (TT: 575 pmol/L vs TG: 633 pmol/L vs GG: 837 pmol/L, P = 0.002) and adolescents (TT: 44 pmol/L vs TG: 58 pmol/L vs GG: 79 pmol/L, P < 0.001). Adolescent boys carrying the genetic variation also had lower levels of LH (TT: 3.0 IU/L vs TG: 2.8 IU/L vs GG: 1.8 IU/L, P = 0.012). Hormone levels in girls and pubertal onset in either sex did not seem to be profoundly affected by the genotypes.
Our findings support recent GWAS results in young adults and expand our understanding of genetic variation affecting AMH levels even in boys prior to the pubertal decline of circulating AMH.