Studies in molecular and genetic epidemiology require a high-throughput, low cost, and reliable means of genomic DNA collection. Buccal (cheek) swabs have been proposed as a means of achieving these goals, but there is little information about the practical application of this approach. From January 1995 to December 1997, we processed 995 buccal swabs for use in polymerase chain reaction (PCR)-based genotype assays in the context of ongoing molecular epidemiologic studies. Six hundred forty-seven of these swabs were processed immediately after collection and 348 were received by mail. We were able to obtain at least one genotype from 99.7% (645 of 647) of fresh-processed and 97.4% (330 of 339) of mailed biosamples. A PCR success rate of 90.3% (2,546 genotypes from 2,819 assays) was achieved. Genotypes were obtained from 96.1% (1, 865 genotypes from 1,941 assays) of fresh-processed biosamples and 77.6% (681 genotypes from 878 assays) of mailed biosamples. PCR success rates at any single locus ranged from 92.6 to 98.8% (fresh-processed) and 75.5 to 79.6% (mailed). The PCR success rate among fresh-processed biosamples was significantly higher than among mailed biosamples (Fisher's exact test p < 0.0001), and more attempts were required to obtain a successful PCR result for mailed biosamples as compared to fresh-processed biosamples. For one locus (CYP3A4), a subset of mailed biosamples was purified if two or more PCR failures occurred. Additional genotypes were obtained in 58.3% of these previously failed biosamples. Time from biosample receipt to DNA extraction had no effect on PCR success. After storage of processed biosamples for as long as 3 years, there was no appreciable decrease in the rate of PCR success. These results suggest that adequate DNA for PCR-based applications can be obtained from buccal swabs, but sampling or processing considerations may be important in obtaining optimal results.

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The National Institute of Environmental Health Sciences (NIEHS) and Brogan & Partners are collaborating with JSTOR to digitize, preserve and extend access to Environmental Health Perspectives. Studies in molecular and genetic epidemiology require a high-throughput, low cost, and reliable means of genomic DNA collection. Buccal (cheek) swabs have been proposed as a means of achieving these goals, but there is little information about the practical application of this approach. From January 1995 to December 1997, we processed 995 buccal swabs for use in polymerase chain reaction (PCR)-based genotype assays in the context of ongoing molecular epidemiologic studies. Six hundred forty-seven of these swabs were processed immediately after col? lection and 348 were received by mail. We were able to obtain at least one genotype from 99.7% (645 of 647) of fresh-processed and 97.4% (330 of 339) of mailed biosamples. A PCR success rate of 90.3% (2,546 genotypes from 2,819 assays) was achieved. Genotypes were obtained from 96.1% (1,865 genotypes from 1,941 assays) of fresh-processed biosamples and 77.6% (681 genotypes from 878 assays) of mailed biosamples. PCR success rates at any single locus ranged from 92.6 to 98.8% (fresh-processed) and 75.5 to 79.6% (mailed). The PCR success rate among fresh-processed biosamples was significantly higher than among mailed biosamples (Fisher's exact test p < 0.0001), and more attempts were required to obtain a successful PCR result for mailed biosamples as compared to fresh-processed biosamples. For one locus (CYP3A4), a subset of mailed biosamples was purified if two or more PCR failures occurred. Additional genotypes were obtained in 58.3% of these previously failed biosamples. Time from biosample receipt to DNA extraction had no effect on PCR success. After storage of processed biosamples for as long as 3 years, there was no appreciable decrease in the rate of PCR success. These results suggest that adequate DNA for PCR-based applications can be obtained from buccal swabs, but sampling or processing considerations may be important in obtaining optimal results. Key wordsr. biosample, genetic epidemiology, molecular epidemiology, polymerase chain reaction. Environ

The melanocortin-1 receptor gene (MC1R) encodes a membrane-bound receptor protein that is central to melanin synthesis. The coding region of MC1R is highly polymorphic and associations of variants with pigmentation phenotypes and risk for cutaneous neoplasms have been reported. We sought to determine the distribution and frequency of MC1R variants and their relationship to pigmentation characteristics in 179 Caucasian controls from the United States. One hundred thirty-five (75.4%) subjects carried one or more variants, and we determined that carriage of the previously designated “red hair color” (RHC) alleles, R151C, R160W, and D294H was strongly associated with fair pigmentation phenotypes including light hair and eye color, tendency to burn, decreased tendency to tan, and freckling. We used SIFT software to define MC1R protein positions that were predicted intolerant to amino acid substitutions; detected variants that corresponded to intolerant substitutions were D84E, R142H, R151C, I155T, R160W, and D294H. Carriage of one or more of these putative functionally important variants or the frameshift variant ins86A was significantly associated with fair pigmentation phenotypes. Analyses limited to carriage of ins86A and the three non-RHC alleles identified by SIFT were attenuated and no longer reached statistical significance. This is the first study to describe MC1R variants among control subjects from the U.S. Our results indicate that the frequency of variants is similar to that previously observed among non-U.S. Caucasians. Risk variants defined by either the published literature or by evolutionary criteria are strongly and significantly associated with all fair pigmentation phenotypes that were measured.