Detecting Monogenic Obesity: A Systematic Exome-Wide Workup of Over 500 Individuals

ABSTRACT Background/Objectives Obesity poses a major public health concern. Although BMI heritability is estimated at 40–80%, genetic diagnostics remain challenging. This study aims to ( i ) assess the diagnostic yield of monogenic obesity in a large patient sample using exome-wide data, ( ii ) identify predictors to improve genetic testing criteria, and ( iii ) evaluate whether the identified genes are included in public obesity gene panels. Subjects/Methods We reviewed the genetic test results of 521 patients with obesity. 84.7% underwent whole-exome analysis, 15.3% were analyzed using a multi-thousand gene panel. Results Monogenic obesity was diagnosed in 5.8% of patients, while 7.1% carried a potentially obesogenic variant. Diagnostic yield was higher in children (6.3%) and patients with syndromic obesity (7.0%). Surprisingly, diagnostic yield was lower in severe obesity cases. 40% of patients with monogenic obesity carried variants in genes not included in current obesity panels. Conclusion Overall, 12.9% of patients had monogenic obesity or a potentially obesogenic variant. These findings suggest that genetic testing should not be limited to patients with extreme obesity. Current obesity panels miss crucial syndromic genes, demonstrating a need for more comprehensive panels and the superiority of whole exome sequencing in obesity.