ESPE Abstracts

Background: Congenital hypogonadotropic hypogonadism (CHH) provides a model to study the impact of sex steroid deficiency on childhood growth.

Aims and objectives: We characterised growth patterns in male CHH patients with special emphasis on growth during the minipuberty of infancy.

Methods: Growth charts of 38 men with CHH (28 from Finland and 10 from Denmark) were evaluated. Fifteen (39%) patients had representative length measurements during the 1st year of life; 8 of them had signs of profound GnRH deficiency (history of micropenis and/or cryptorchidism). Sixteen men (42%) had molecular genetic diagnosis of CHH (mutations in KAL1 in 7, FGFR1 in 5, GNRHR in 2, CDH7 in 1, and PROK2 in 1 patient).

Results: The mean (± SD) length standard deviation score (SDS) at birth (0.2±1.6 SDS) decreased significantly during the first 3 (to −0.9±1.2 SDS, P<0.01) and 6 months of life (to −0.7±1.3 SDS, P<0.05). The respective mean length SDSs were lower than the mean mid-parental target height (MPH) (P<0.05). Importantly, the length SDS deflected strongly in those with signs of profound GnRH deficiency from 0.8±1.8 SDS at birth to −1.0±1.4 SDS at 3 months of age (P<0.01); and to −0.5±1.2 SDS at 6 months of age (P<0.05). During the first 6 months of life, CHH patients grew thinner (mean change in weight-for-length, −6.7±11%, P<0.05). Between 6 and 8 years or age, height SDSs were, on average, −0.8±1.3 below the mean MPH (P<0.05), and the boys were shorter than the general population (P<0.01). At an average age of 15.8±0.8 years, height SDS reached its nadir (−1.8±1.4 SDS), reflecting pubertal failure. Final heights, however, did not differ from MPH (P=NS).

Conclusions: Sex steroids modulate human growth during the first few months of life. Moderate length deflection in infancy is a novel non-reproductive feature of CHH.

Funding information: The Finnish Foundation of Pediatric Research, the Academy of Finland, the Helsinki University Central Hospital Research Funds, Emil Aaltonen and the Sigrid Juselius Foundation. COST BM1105.