Minority Health and Health Equity Archive

Permanent URI for this collectionhttp://hdl.handle.net/1903/21769

Welcome to the Minority Health and Health Equity Archive (MHHEA), an electronic archive for digital resource materials in the fields of minority health and health disparities research and policy. It is offered as a no-charge resource to the public, academic scholars and health science researchers interested in the elimination of racial and ethnic health disparities.

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Author: search.filters.author.Reich, DavidSubject: search.filters.subject.Genetics and Race

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    Results from a prostate cancer admixture mapping study in African-American men.
    (2009) Bock, Cathryn Hufford; Schwartz, Ann G; Ruterbusch, Julie J; Levin, Albert M; Neslund-Dudas, Christine; Land, Susan J; Wenzlaff, Angela S; Reich, David; McKeigue, Paul; Chen, Wei; Heath, Elisabeth I; Powell, Isaac J; Kittles, Rick A; Rybicki, Benjamin A
    There are considerable racial disparities in prostate cancer risk, with a 60% higher incidence rate among African-American (AA) men compared with European-American (EA) men, and a 2.4-fold higher mortality rate in AA men than in EA men. Recently, studies have implicated several African-ancestry associated prostate cancer susceptibility loci on chromosome 8q24. In the current study, we performed admixture mapping in AA men from two independent case-control studies of prostate cancer to confirm the 8q24 ancestry association and also identify other genomic regions that may harbor prostate cancer susceptibility genes. A total of 482 cases and 261 controls were genotyped for 1,509 ancestry informative markers across the genome. The mean estimated individual admixture proportions were 20% European and 80% African. The most significant observed increase in European ancestry occurred at rs2141360 on chromosome 7q31 in both the case-only (P = 0.0000035) and case-control analyses. The most significant observed increase in African ancestry across the genome occurred at a locus on chromosome 5q35 identified by SNPs rs7729084 (case-only analysis P = 0.002), and rs12474977 (case-control analysis P = 0.004), which are separated by 646 kb and were adjacent to one another on the panel. On chromosome 8, rs4367565 was associated with the greatest excess African ancestry in both the case-only and case-control analyses (case-only and case-control P = 0.02), confirming previously reported African-ancestry associations with chromosome 8q24. In conclusion, we confirmed ancestry associations on 8q24, and identified additional ancestry-associated regions potentially harboring prostate cancer susceptibility loci.
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    Admixture mapping identifies 8q24 as a prostate cancer risk locus in African-American men
    (2006) Freedman, Matthew L.; Haiman, Christopher A.; Patterson, Nick; McDonald, Gavin J.; Tandon, Arti; Waliszewska, Alicja; Penney, Kathryn; Steen, Robert G.; Kristin Ardlie, Kristin; John, Esther M.; Oakley-Girvan, Ingrid; Whittemore, Alice S.; Cooney, Kathleen A.; Ingles, Sue A.; Altshuler, David; Henderson, Brian E.; Reich, David
    A whole-genome admixture scan in 1,597 African Americans identified a 3.8Mbinterval on chromosome 8q24 as significantly associated with susceptibility to prostate cancer [logarithm of odds (LOD)7.1]. The increased risk because of inheriting African ancestry is greater in men diagnosed before 72 years of age (P < 0.00032) and may contribute to the epidemiological observation that the higher risk for prostate cancer in African Americans is greatest in younger men (and attenuates with older age). The same region was recently identified through linkage analysis of prostate cancer, followed by fine-mapping. We strongly replicated this association (P<4.2109) but find that the previously described alleles do not explain more than a fraction of the admixture signal. Thus, admixture mapping indicates a major, still-unidentified risk gene for prostate cancer at 8q24, motivating intense work to find it.
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    A High-Density Admixture Map for Disease Gene Discovery in African Americans
    (2004) Smith, Michael W; Patterson, Nick; Lautenberger, James A; Truelove, Ann L; McDonald, Gavin J; Waliszewska, Alicja; Kessing, Bailey D; Malasky, Micahel J; Scafe, Charles; Le, Ernest; De Jager, Philip L; Mignault, Andre A; Yi, Zeng; de The, Guy; Essex, Myron; Sankale, Jean-Louis; Moore, Jason H; Poku, Kwabena; Phair, John P; Goedert, James J; Vlahov, David; Williams, Scott M; Tishkoff, Sarah A; Winkler, Cheryl A; De La Vega, Francisco M; Woodage, Trevor; Sninsky, John J; Hafler, David A; Altshuler, David; Gilbert, Dennis A; O'Brien, Stephen J; Reich, David
    Admixture mapping (also known as “mapping by admixture linkage disequilibrium,” or MALD) provides a way of localizing genes that cause disease, in admixed ethnic groups such as African Americans, with ∼100 times fewer markers than are required for whole-genome haplotype scans. However, it has not been possible to perform powerful scans with admixture mapping because the method requires a dense map of validated markers known to have large frequency differences between Europeans and Africans. To create such a map, we screened through databases containing ∼450,000 single-nucleotide polymorphisms (SNPs) for which frequencies had been estimated in African and European population samples. We experimentally confirmed the frequencies of the most promising SNPs in a multiethnic panel of unrelated samples and identified 3,011 as a MALD map (1.2 cM average spacing).We estimate that this map is ∼70% informative in differentiating African versus European origins of chromosomal segments. This map provides a practical and powerful tool, which is freely available without restriction, for screening for disease genes in African American patient cohorts. The map is especially appropriate for those diseases that differ in incidence between the parental African and European populations.