Genetic variation in LMNA modulates plasma leptin and indices of obesity in aboriginal Canadians.

We previously showed that a rare mutation in LMNA, which encodes lamins A and C, underlies autosomal dominant Dunnigan-type familial partial lipodystrophy (FPLD). Because FPLD is an extreme example of genetically disturbed adipocyte differentiation, it is possible that common variation in LMNA is associated with obesity-related phenotypes. We therefore analyzed the relationships between the common LMNA 1908T/C single nucleotide polymorphism (SNP) and plasma leptin and anthropometric indices in 306 nondiabetic Canadian Oji-Cree. We found that subjects with the LMNA 1908T/1908T genotype had significantly higher plasma leptin than the subjects with either the 1908C/1908T or 1908C/1908C genotypes, after adjustment for age and sex. Physical indices of obesity, such as body mass index, percent body fat, and ratio of waist-to-hip circumference, were also higher among Oji-Cree subjects with the LMNA 1908T/1908T genotype than the subjects with either the 1908C/1908T or 1908C/1908C genotypes. The results suggest that common genetic variation in LMNA may be an important determinant of plasma leptin and obesity-related quantitative traits.