NGS panels for severe obesity in youths reveal high VOUS rates and limited clinical stratification utility
The study reports a cross-sectional analysis of 164 youths with severe obesity who underwent prior next-generation sequencing targeting the leptin-MC4R pathway and ciliopathy-related genes. Investigators found that 54.5% carried at least one variant, with the vast majority classified as variants of uncertain significance, while pathogenic or likely pathogenic findings accounted for only 11% and showed no significant differences in metabolic or behavioural phenotypes compared to controls. These results underscore the current limitations of broad genetic testing for obesity in routine diagnostics. The authors recommend restricting such molecular workups to specialised obesity clinics and research settings until variant interpretation improves through functional studies and longitudinal phenotyping.
The original study
Variants in the leptin-MC4R pathway and ciliopathy-related genes in youths with obesity beyond hyperphagia and early onset.
- Authors
- Manco M, Ravà L, Aureli A, Scoppola V, Mariani M, Aniello F, et al.
- Journal
- Journal of endocrinological investigation
- Type
- Journal Article
- PMID
- 42424029
Original abstract
PURPOSE: To investigate the prevalence, classification, and clinical impact of genetic variants in leptin-melanocortin (MC4R) pathway- and ciliopathy related genes, and in some key neurodevelopmental and pleiotropic genes whose dysfunction may cause hyperphagia in a sample of youths with severe obesity regardless of age of obesity onset and presence of hyperphagia. METHODS: Cross-sectional evaluation of patients consecutively referred for severe obesity having had prior next-generation sequencing targeting genes of interest as for the Rare Obesity Advanced Diagnosis (ROAD) program gene panel. Variants were classified according to guidelines as likely benign (LB), pathogenic (P), likely pathogenic (LP), or variants of uncertain significance (VOUS). Clinical and metabolic features were compared across groups of controls (mutant negative and LB carriers), VOUS, and LP/P carriers. RESULTS: A total of 164 patients were included: 91 patients (54.5%) carried at least one variant. Most variants were heterozygous and classified as VOUS (n = 82, 89%); 10 patients (11%) had LP/P variants. Genes most frequently associated with LP/P findings included MC4R (n = 2), ALMS1 (n = 3), and CEP290 (n = 2). No significant differences were found across groups in obesity degree, lipid profile, glucose metabolism, or behavioural symptoms. A non-significant trend toward earlier onset of obesity was observed in the LP/P group. CONCLUSION: Children with severe obesity often carry gene variants in the leptin-MC4R pathway or associated to ciliopathies, which appear even in cohorts unselected for early onset or hyperphagia. Their clinical significance remains uncertain. Although genetic testing may inform clinical stratification and personalised treatment, its integration into the diagnostic workup of severe obesity should currently be restricted to specialised obesity clinics and research contexts. Findings highlight the need for improved interpretation of LP and VOUS through functional studies and long-term phenotyping.