Characterization of minipuberty in infants with Prader-Willi syndrome

Background: Minipuberty describes transient activation of the hypothalamic-pituitary-gonadal axis occurring during the first few months of life. Hormone levels during minipuberty were described in only a few Prader-Willi syndrome (PWS) infant boys and have not been reported in PWS infant girls. Objectives: To measure gonadotropins and gonadal hormones in PWS male and female infants and assess gender-specific patterns of hormone secretion. Methods: Hormone levels in 14 (9 male, 5 female) PWS infants ages 1-3 months were compared with reference ranges for normal infants and in 44 prepubertal PWS children (27 female, 17 male). Results: Compared to prepubertal boys, hormone levels (median and range) for PWS infant boys were increased: LH 2.8 mIU/ml (1.2-6.2), FSH 4.4 mIU/ml (1.0-19.5), testosterone 4.0 nmol/l (3.0-7.0), inhibin B 219 pg/ml (141-325), and AMH 79 ng/ml (45-157). Hormone levels in infant girls were not significantly different from levels in prepubertal girls. LH, inhibin B, and AMH were higher in male infants than in female infants. LH/FSH ratios were 0.56 (0.24-1.77) in boys versus 0.09 (0.04-0.17) in girls (p = 0.003). Conclusions: Hormone levels in PWS infant boys are in the expected minipuberty range. By contrast, reproductive hormones in most PWS infant girls did not differ from levels in prepubertal girls. © 2014 S. Karger AG, Basel.