Ontology highlight
ABSTRACT: Context
Loss-of-function mutations in PROK2 and PROKR2 have been implicated in Kallmann syndrome (KS), characterized by hypogonadotropic hypogonadism and anosmia. Recent data suggest overlapping phenotypes/genotypes between KS and congenital hypopituitarism (CH), including septo-optic dysplasia (SOD).Objective
We screened a cohort of patients with complex forms of CH (n = 422) for mutations in PROK2 and PROKR2.Results
We detected 5 PROKR2 variants in 11 patients with SOD/CH: novel p.G371R and previously reported p.A51T, p.R85L, p.L173R, and p.R268C-the latter 3 being known functionally deleterious variants. Surprisingly, 1 patient with SOD was heterozygous for the p.L173R variant, whereas his phenotypically unaffected mother was homozygous for the variant. We sought to clarify the role of PROKR2 in hypothalamopituitary development through analysis of Prokr2(-/-) mice. Interestingly, these revealed predominantly normal hypothalamopituitary development and terminal cell differentiation, with the exception of reduced LH; this was inconsistent with patient phenotypes and more analogous to the healthy mother, although she did not have KS, unlike the Prokr2(-/-) mice.Conclusions
The role of PROKR2 in the etiology of CH, SOD, and KS is uncertain, as demonstrated by no clear phenotype-genotype correlation; loss-of-function variants in heterozygosity or homozygosity can be associated with these disorders. However, we report a phenotypically normal parent, homozygous for p.L173R. Our data suggest that the variants identified herein are unlikely to be implicated in isolation in these disorders; other genetic or environmental modifiers may also impact on the etiology. Given the phenotypic variability, genetic counseling may presently be inappropriate.
SUBMITTER: McCabe MJ
PROVIDER: S-EPMC3612801 | biostudies-literature | 2013 Mar
REPOSITORIES: biostudies-literature
McCabe Mark J MJ Gaston-Massuet Carles C Gregory Louise C LC Alatzoglou Kyriaki S KS Tziaferi Vaitsa V Sbai Oualid O Rondard Philippe P Masumoto Koh-hei KH Nagano Mamoru M Shigeyoshi Yasufumi Y Pfeifer Marija M Hulse Tony T Buchanan Charles R CR Pitteloud Nelly N Martinez-Barbera Juan-Pedro JP Dattani Mehul T MT
The Journal of clinical endocrinology and metabolism 20130205 3
<h4>Context</h4>Loss-of-function mutations in PROK2 and PROKR2 have been implicated in Kallmann syndrome (KS), characterized by hypogonadotropic hypogonadism and anosmia. Recent data suggest overlapping phenotypes/genotypes between KS and congenital hypopituitarism (CH), including septo-optic dysplasia (SOD).<h4>Objective</h4>We screened a cohort of patients with complex forms of CH (n = 422) for mutations in PROK2 and PROKR2.<h4>Results</h4>We detected 5 PROKR2 variants in 11 patients with SOD/ ...[more]