Coding Variant In  LEP Associated with Lower Leptin Concentrations Implicates Leptin in the Regulation of Early Adiposity

Leptin influences food intake by informing the brain about the status of body fat stores. Rare LEP mutations associated with congenital leptin deficiency cause severe early-onset obesity that can be mitigated by administering leptin. However, the role of genetic regulation of leptin concentrations in polygenic obesity remains poorly understood. We performed an exome-based analysis in up to 57,232 individuals of diverse ancestries to identify genetic variants that influence adiposity-adjusted leptin concentrations. We confirmed five previously established and identified five novel variants, including four missense variants, in LEP, ZNF800, KLHL31, and ACTL9, and one intergenic variant near KLF14. The novel missense Val94Met (rs17151919) variant in LEP was common in individuals with African ancestry (minor allele frequency (MAF) AFR= 8%; MAF EUR= 0.02%) and was associated with 0.34 standard deviations lower leptin concentrations per Met94 allele in adults (P= 2x10-16, n= 3,901). Using in vitro analyses, we showed that the Met94 allele decreases leptin secretion (P= 0.025). The Met94 allele was associated with higher BMI in young African-ancestry children (P= 0.002, n= 2,030) but not in adults, suggesting leptin regulates early adiposity.