ESPEYB18 7. Puberty Clinical Guidance (7 abstracts)
Hum Reprod. 2020 Oct 1;35(10):23122322. 10.1093/humrep/deaa185. PMID: 32862222. https://academic.oup.com/humrep/article/35/10/2312/5899242
In brief: This study shows that both the GnRH stimulation test and serum inhibin B have insufficient specificity to discriminate congenital hypogonadotropic hypogonadism (CHH) from constitutional delay of growth and puberty (CDGP).
Comment: CDGP is common and difficult to differentiate from CHH, in particular when CHH is not accompanied by cryptorchidism/micropenis or additional syndromic features (1). This study included 74 males with CDGP aged 14-18 years and 127 males with CHH. CDGP was confirmed by complete spontaneous puberty after the age of 18 years. LH response to GnRH was very variable among CHH patients and was positively correlated with testicular volume. LH response in CDGP patients was also variable and overlapped with CHH patients. Notably, no CDGP patient had an LH peak <4 IU/L. Inhibin B was significantly lower in CHH patients than in CDGP, but values often overlapped. All CDGP patients had inhibin B levels >35 pg/ml.
This study presents a large cohort of male patients for which the diagnosis of CHH or CDGP had been carefully confirmed. Testicular volume and basal testosterone did not significantly differ between both groups. Overlapping values of stimulated LH and inhibin B suggest that neither test is able to discriminate between CDGP and CHH patients with milder GnRH deficiency. The authors propose to offer genetic testing to adolescents with low gonadotropins as mutations in CHH genes are very rare in patients with CDGP (2).
Reference: 1. Palmert MR, Dunkel L (2012) Clinical practice. Delayed puberty. N. Engl. J. Med. 366:443453.2. Cassatella D, Howard SR, Acierno JS, Xu C, Papadakis GE, Santoni FA, Dwyer AA, Santini S, Sykiotis GP, Chambion C, Meylan J, Marino L, Favre L, Li J, Liu X, Zhang J, Bouloux PM, Geyter C, Paepe A, Dhillo WS, Ferrara JM, Hauschild M, Lang-Muritano M, Lemke JR, Flück C, Nemeth A, Phan-Hug F, Pignatelli D, Popovic V, Pekic S, Quinton R, Szinnai G, lAllemand D, Konrad D, Sharif S, Iyidir ÖT, Stevenson BJ, Yang H, Dunkel L, Pitteloud N. (2018) Congenital hypogonadotropic hypogonadism and constitutional delay of growth and puberty have distinct genetic architectures. Eur. J. Endocrinol. 178:377388.