Abstract
BACKGROUND: Early childhood obesity poses a significant global public health challenge, necessitating the identification of treatable causes, particularly congenital leptin deficiencies. Serum leptin level measurement aids in diagnosing these rare contributors, guiding effective management. METHODS: A Chinese family with early-onset obesity underwent LEP mutational screening via direct sequencing. mRNA expression and protein stability patterns of LEP were separately analyzed using qPCR and bioinformatics. RESULTS: We present a case of a 12.5-year-old girl born to non-obese, non-consanguineous Chinese parents, exhibiting low leptin levels. Leptin gene sequencing revealed novel compound heterozygous mutations in exon 3. RT-PCR analysis showed the mutation didn't affect leptin production. Bioinformatics analysis indicated the variant rendered the leptin protein unstable. CONCLUSION: Loss-of-function mutations in LEP underlies early-onset obesity in the patient.