Normosmic idiopathic hypogonadotropic hypogonadism due to a novel GNRH1 variant in two siblings

SUMMARY: Hypogonadotropic hypogonadism is characterised by insufficient secretion of pituitary gonadotropins resulting in delayed puberty, anovulation and azoospermia. When hypogonadotropic hypogonadism occurs in the absence of structural or functional lesions of the hypothalamic or pituitary gland, the hypogonadism is defined as idiopathic hypogonadotropic hypogonadism (IHH). This is a rare genetic disorder caused by a defect in the secretion of gonadotropin releasing hormone (GNRH) by the hypothalamus or a defect in the action of GNRH on the pituitary gland. Up to 50% of IHH cases have identifiable pathogenic variants in the currently known genes. Pathogenic variants in the GNRHR gene encoding the GNRH receptor are a relatively common cause of normosmic IHH, but reports of pathogenic variants in GNRH1 encoding GNRH are exceedingly rare. We present a case of two siblings born to consanguineous parents who were found to have normosmic idiopathic hypogonadotropic hypogonadism due to homozygosity of a novel loss-of function variant in GNRH1. Case 1 is a male who presented at the age of 17 years with delayed puberty and under-virilised genitalia. Case 2 is a female who presented at the age of 16 years with delayed puberty and primary amenorrhea.

LEARNING POINTS: IHH is a genetically heterogeneous disorder which can be caused by pathogenic variants affecting proteins involved in the pulsatile gonadotropin-releasing hormone release, action, or both. Currently known genetic defects account for up to 50% of all IHH cases. GNRH1 pathogenic variants are a rare cause of normosmic IHH. IHH is associated with a wide spectrum of clinical manifestations. IHH can be challenging to diagnose, particularly when attempting to differentiate it from constitutional delay of puberty. Early diagnosis and gonadotrophin therapy can prevent negative physical sequelae and mitigate psychological distress with the restoration of puberty and fertility in affected individuals.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:2020

Enthalten in:

Endocrinology, diabetes & metabolism case reports - 2020(2020) vom: 05. März

Sprache:

Englisch

Beteiligte Personen:

Sagi, Satyanarayana V [VerfasserIn]
Joshi, Hareesh [VerfasserIn]
Whiles, Emily [VerfasserIn]
Hikmat, Mondy [VerfasserIn]
Puthi, Vijith R [VerfasserIn]
MacDougall, Jane [VerfasserIn]
Spiden, Sarah L [VerfasserIn]
Fuller, Gavin [VerfasserIn]
Park, Soo-Mi [VerfasserIn]
Oyibo, Samson O [VerfasserIn]

Links:

Volltext

Themen:

2020
Adult
Asian - Pakistani
Female
Genetics
Gynaecology
Insight into disease pathogenesis or mechanism of therapy
Journal Article
Male
March
Paediatrics
Pituitary
United Kingdom
Urology

Anmerkungen:

Date Revised 27.02.2024

published: Print-Electronic

Citation Status Publisher

doi:

10.1530/EDM-19-0145

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM307257185