Julie Steenhuysen (Reuters) reported on a recent study published in PLoS Genetics which found that genes that helped early humans adapt to cold climates may be driving metabolism-related diseases such as obesity or diabetes. U.S. researchers at the University of Chicago found a strong correlation between climate and genetic adaptations that influence the risk of metabolic syndrome, a group of related disorders such as obesity, high cholesterol, heart disease and diabetes. “Climate over a long period of time has shaped the distribution of genetic variants that may be associated with the risk of these common metabolic disorders,” said Anna Di Rienzo, a professor of human genetics at the University of Chicago. Anthropologists have long argued that differences in skin pigmentation, for instance, are related to early human migration. “There are all of these traits, body mass or skin pigmentation, that we know are strongly correlated with environmental variables,” Di Rienzo said. Di Rienzo and colleagues wanted to see if genes that were once useful for tolerating cold climates were playing a role in metabolic diseases. “To survive in these climates, they had to adapt,” said Di Rienzo.

To test the hypothesis that climate shaped variation in metabolism genes in humans, the team used a bioinformatics approach to select 82 candidate genes for common metabolic disorders. They then genotyped 873 tag SNPs in the genes in 1,034 people from 54 populations. They saw several clusters of different genetic variations related to metabolic syndrome in colder climates. Interestingly, one haplotype was associated with higher body mass index and altered concentrations of the hunger-satiety hormones ghrelin and leptin, suggesting that it conferred a selective advantage on energy metabolism. Biotech Mashup thinks that we might be able to use some of the SNPs from this study to better understand our hunger pains. Furthermore, the SNP tests offered by companies such as 23andme and Navigenics might be more insightful in light of these studies.

The New York Times is reporting that patients are submitting to underground genetic testing, but are not informing their doctors of the results because these patients have legitimate fears of insurance discrimination. With recent advancements in technology, companies such as 23andMe and deCODEme have been able to remove the last barrier, cost, for personalized genetic screening. 

The article addresses issues regarding privacy fears, in addition to the use of genetic results to prescreen policies/increase the cost of premiums by insurance companies.  An admittance by some insurance companies in a recent Georgetown University Health Policy Institute study is frightening; they admit they would raise premiums or deny coverage based on genetic results.

It is disheartening that fears of discrimination by insurance companies are hindering the advent of new genetic tests to help patients make informed medical decisions before undergoing treatment. Hope is on the horizon; the Genetic Information Nondiscrimination Act would make it illegal for insurers to deny coverage based solely on a genetic predisposition.  We wait for the passage of this act as this bill is before the congress for a seventh time.