Triallelic digenic mutation in the prokineticin 2 and GNRH receptor genes in two brothers with normosmic congenital hypogonadotropic hypogonadism

Abstract

Purpose/aim of the study: To date, different genes have been identified as responsible for the presence of normosmic congenital hypogonadotropic hypogonadism (nCHH). Herein, we report the molecular findings regarding the analysis of PROK2, in two brothers with nCHH. Subjects and methods: Two siblings with nCHH, in whom mutations in GNRHR, PROKR2 and FGFR1 had been investigated previously, as well as their family were studied. DNA was amplified by PCR and sequenced for the PROK2 gene. Controls were analyzed by restriction fragment-length polymorphism. The structure of PROK2 and its mutant protein were compared using a protein molecular model. Results: Both affected siblings exhibited a heterozygous p.R117W mutation in PROK2, while their mother was a heterozygous carrier and their father, an unaffected brother and their sister were homozygous wild type. Besides, both patients presented a homozygous p.E90K mutation in GNRHR that had been previously reported. Conclusions: We found a novel mutation in PROK2 in two siblings in whom a mutation in the GNRHR gene had been previously reported.

• GNRHR
• molecular modeling
• nCHH
• PROK2
• triallelic digenic mutations

Declaration of interest

All authors declare that there are no conflicts of interest. This work was partially supported by the Patronage of the Institute of Ophthalmology “Conde de Valenciana”, México, D.F., México.