An autosomal genomic scan for loci linked to plasma leptin concentration in Pima Indians

OBJECTIVE: To identify chromosomal regions linked to plasma leptin concentr ations. DESIGN: Autosomal genome-wide scan, including 516 microsatellite markers. S ib-pair (Haseman-Elston) and variance components methods were used to asses s genetic linkage. SUBJECTS: 770 Pima Indians comprising 239 nuclear families (for a total of 1199 sibling-pairs). MEASUREMENTS: Plasma leptin concentrations and body mass index (BMI), adjus ted for age and sex. RESULTS: The strongest evidence for linkage with plasma leptin concentratio n was on chromosome 6p logarithm of odds (LOD) = 2.1 by variance components analysis. There was no evidence for linkage to BMI in this region. Additio nal regions with marginal evidence for linkage to plasma leptin concentrati on (LOD greater than or equal to 1.0) were detected on chromosomes 3, 11, 1 3, 15 and 16. CONCLUSIONS: The results suggest that a locus on chromosome 6p influences p lasma leptin concentrations. Replication studies are needed to exclude the possibility that linkage has been falsely detected.