 Genomimic screen for substance dependence and body mass index in southwest California  Indians
Genomimic screen for substance dependence and body mass index in southwest California  IndiansGenes, Brain and Behavior 6 (2), 184–191.
- Cindy L. Ehlers*,
 C.L. Ehlers, 10550 N. Torrey Pines  Road, CVN-14, La Jolla, CA, USA. E-mail cindye@scripps.edu C.L. Ehlers, 10550 N. Torrey Pines  Road, CVN-14, La Jolla, CA, USA. E-mail cindye@scripps.edu Departments of Molecular  and Experimental Medicine and Neuropharmacology, The Scripps Research  Institute Departments of Molecular  and Experimental Medicine and Neuropharmacology, The Scripps Research  Institute
- Kirk C. Wilhelmsen  
- Departments of Genetics and Neurology, The Carolina Center for Genome Sciences and the Bowles Center for Alcohol Studies, University of North Carolina, CA, USA
Abstract
Substance abuse and obesity are health disparities that  may afflict Native Americans more than some other ethnic groups.   One theoretical  assumption concerning Native people is that the long history of dependence on  foraging and subsistence agriculture may have led to selective enrichment of  traits that improve genetic fitness, so called ‘thrifty’ or ‘fat sparing’ genes.
We have speculated that this same selective pressure may have enriched for  genetic variants that increase the risk for consumption of alcohol and drugs of  abuse.
Here, we report the results of a genome scan that compared findings for  two consumption phenotypes: ‘any drug dependence and/or regular tobacco use’ and  body mass index (BMI) in southwest California (SWC) Indian families.
Variance  component analyses from SOLAR were used to generate log of the odds ratio (LOD)  scores.
Evidence for linkage was found on chromosome 6 for both the ‘any drug’  (LOD score = 3.3) and BMI (LOD score = 2.3) phenotypes. Bivariate analyses of  the two phenotypes revealed a combined LOD score of 4.1 at that location.
Additional loci on chromosomes 6, 15, 16 and 21 were found for the ‘any drug’  phenotype, and on chromosomes 8, 16 and 18 for BMI (LOD scores ranged between  1.2 and 2.3).
These results provide suggestive evidence for linkage for substance abuse and BMI in this Mission Indian population and, furthermore, provide preliminary data suggesting that ‘consumption phenotypes’ may share some genetic determinants.
 
