Monogenic etiologies in a cohort of early onset obesity: a real-world experience from Belgium

IntroductionObesity is a major global health issue with multifactorial etiologies. Among them, recent advances in the comprehension of eating and energy regulation showed that around 60 genes involved in the hypothalamic leptin/melanocortin pathway contribute to the development of rare monogenic or...

Full description

Saved in:
Bibliographic Details
Main Authors: Julie Harvengt, Muriel Hannon, Leonor Palmeira, Marie-Christine Lebrethon, Vinciane Dideberg, Vincent Bours
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-08-01
Series:Frontiers in Endocrinology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fendo.2025.1608398/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849247394039857152
author Julie Harvengt
Julie Harvengt
Muriel Hannon
Leonor Palmeira
Leonor Palmeira
Marie-Christine Lebrethon
Vinciane Dideberg
Vincent Bours
Vincent Bours
author_facet Julie Harvengt
Julie Harvengt
Muriel Hannon
Leonor Palmeira
Leonor Palmeira
Marie-Christine Lebrethon
Vinciane Dideberg
Vincent Bours
Vincent Bours
author_sort Julie Harvengt
collection DOAJ
description IntroductionObesity is a major global health issue with multifactorial etiologies. Among them, recent advances in the comprehension of eating and energy regulation showed that around 60 genes involved in the hypothalamic leptin/melanocortin pathway contribute to the development of rare monogenic or syndromic forms of obesity.ObjectiveTo better delineate the genetic diagnostic rate and the phenotype in a cohort of early onset obesity and to integrate our results in guidance for genetic testing.MethodsIn a diagnostic setting, 223 patients with early onset obesity were screened through a targeted panel including 44 genes for severe early onset obesity. Genetic results and clinical descriptions were reviewed for the entire cohort.ResultsA diagnostic yield of 3.1% was established. Likely pathogenic or pathogenic variants were found in MRAP2, MC4R, BBS2, and BBS4, and a 16p11.2 deletion was confirmed. Clinically, 23% of the cohort had early onset obesity at <1 year, 47% at 1–4 years, and 30% at >4 years. No discriminative clinical feature appears to enhance the diagnostic yield. Thirty-six percent of the cohort presented additional neurological complaints that led to more extensive genetic investigations with a diagnosis rate of 1.8% in this subgroup.ConclusionOur work found a diagnostic yield of 3.1%. Additionally, 19.7% of heterozygous variants of unknown significance were found in genes related to autosomal conditions and 34.9% in genes related to recessive conditions. These results highlight the need for accurate genotype-phenotype correlations. Genetic laboratory expertise in obesity is highly recommended, especially in the context of the availability of new targeted anti-obesity therapies that open the field for current and future perspectives of these targeted genetic investigations.
format Article
id doaj-art-07cfba37530a45369840b063ed2a0d61
institution Kabale University
issn 1664-2392
language English
publishDate 2025-08-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Endocrinology
spelling doaj-art-07cfba37530a45369840b063ed2a0d612025-08-20T03:58:14ZengFrontiers Media S.A.Frontiers in Endocrinology1664-23922025-08-011610.3389/fendo.2025.16083981608398Monogenic etiologies in a cohort of early onset obesity: a real-world experience from BelgiumJulie Harvengt0Julie Harvengt1Muriel Hannon2Leonor Palmeira3Leonor Palmeira4Marie-Christine Lebrethon5Vinciane Dideberg6Vincent Bours7Vincent Bours8Human Genetics Department, CHU of Liège, Liège, BelgiumGIGA Research, University of Liège, Liège, BelgiumHuman Genetics Department, CHU of Liège, Liège, BelgiumHuman Genetics Department, CHU of Liège, Liège, BelgiumGIGA Research, University of Liège, Liège, BelgiumPediatric Endocrinology, Pediatric Department, CHU of Liège, Liège, BelgiumHuman Genetics Department, CHU of Liège, Liège, BelgiumHuman Genetics Department, CHU of Liège, Liège, BelgiumGIGA Research, University of Liège, Liège, BelgiumIntroductionObesity is a major global health issue with multifactorial etiologies. Among them, recent advances in the comprehension of eating and energy regulation showed that around 60 genes involved in the hypothalamic leptin/melanocortin pathway contribute to the development of rare monogenic or syndromic forms of obesity.ObjectiveTo better delineate the genetic diagnostic rate and the phenotype in a cohort of early onset obesity and to integrate our results in guidance for genetic testing.MethodsIn a diagnostic setting, 223 patients with early onset obesity were screened through a targeted panel including 44 genes for severe early onset obesity. Genetic results and clinical descriptions were reviewed for the entire cohort.ResultsA diagnostic yield of 3.1% was established. Likely pathogenic or pathogenic variants were found in MRAP2, MC4R, BBS2, and BBS4, and a 16p11.2 deletion was confirmed. Clinically, 23% of the cohort had early onset obesity at <1 year, 47% at 1–4 years, and 30% at >4 years. No discriminative clinical feature appears to enhance the diagnostic yield. Thirty-six percent of the cohort presented additional neurological complaints that led to more extensive genetic investigations with a diagnosis rate of 1.8% in this subgroup.ConclusionOur work found a diagnostic yield of 3.1%. Additionally, 19.7% of heterozygous variants of unknown significance were found in genes related to autosomal conditions and 34.9% in genes related to recessive conditions. These results highlight the need for accurate genotype-phenotype correlations. Genetic laboratory expertise in obesity is highly recommended, especially in the context of the availability of new targeted anti-obesity therapies that open the field for current and future perspectives of these targeted genetic investigations.https://www.frontiersin.org/articles/10.3389/fendo.2025.1608398/fullearly-onset obesitymonogenic obesityMC4RBardet–Biedl syndromehypothalamic obesity
spellingShingle Julie Harvengt
Julie Harvengt
Muriel Hannon
Leonor Palmeira
Leonor Palmeira
Marie-Christine Lebrethon
Vinciane Dideberg
Vincent Bours
Vincent Bours
Monogenic etiologies in a cohort of early onset obesity: a real-world experience from Belgium
Frontiers in Endocrinology
early-onset obesity
monogenic obesity
MC4R
Bardet–Biedl syndrome
hypothalamic obesity
title Monogenic etiologies in a cohort of early onset obesity: a real-world experience from Belgium
title_full Monogenic etiologies in a cohort of early onset obesity: a real-world experience from Belgium
title_fullStr Monogenic etiologies in a cohort of early onset obesity: a real-world experience from Belgium
title_full_unstemmed Monogenic etiologies in a cohort of early onset obesity: a real-world experience from Belgium
title_short Monogenic etiologies in a cohort of early onset obesity: a real-world experience from Belgium
title_sort monogenic etiologies in a cohort of early onset obesity a real world experience from belgium
topic early-onset obesity
monogenic obesity
MC4R
Bardet–Biedl syndrome
hypothalamic obesity
url https://www.frontiersin.org/articles/10.3389/fendo.2025.1608398/full
work_keys_str_mv AT julieharvengt monogenicetiologiesinacohortofearlyonsetobesityarealworldexperiencefrombelgium
AT julieharvengt monogenicetiologiesinacohortofearlyonsetobesityarealworldexperiencefrombelgium
AT murielhannon monogenicetiologiesinacohortofearlyonsetobesityarealworldexperiencefrombelgium
AT leonorpalmeira monogenicetiologiesinacohortofearlyonsetobesityarealworldexperiencefrombelgium
AT leonorpalmeira monogenicetiologiesinacohortofearlyonsetobesityarealworldexperiencefrombelgium
AT mariechristinelebrethon monogenicetiologiesinacohortofearlyonsetobesityarealworldexperiencefrombelgium
AT vincianedideberg monogenicetiologiesinacohortofearlyonsetobesityarealworldexperiencefrombelgium
AT vincentbours monogenicetiologiesinacohortofearlyonsetobesityarealworldexperiencefrombelgium
AT vincentbours monogenicetiologiesinacohortofearlyonsetobesityarealworldexperiencefrombelgium