370 likes | 407 Views
Explore pharmacogenetics, population structure, and genetic admixture in drug responses and race specificity. Learn about the promise of personalized therapy and the impact of genetic variations on drug metabolism.
E N D
PHARMACOGENETICS, POPULATION STRUCTURE AND ADMIXTURE Guilherme Suarez-Kurtz Rio de Janeiro - Brazil RS-ICSU-IAP 2006
Pharmacogenetics deals with drug responses (therapeutic or adverse) and their modification by hereditary factors.
O M P H A R M A C O G E N E T I C S O M P H A R M A C O G E N I C S Pharmacogenomics is pharmacogenetics with two SNPs
THE CURRENT PARADIGM one drug/one dose fits all
THE PHARMACOGENETICS PROMISE personalised therapy ”paradigm-disrupting”
PHARMACOGENETIC DATABASES • Population frequencies of many polymorphic genes of pharmacogenetic interest depend on race or ethnic specificity. • Information about ethnic specificity has become an integral part of pharmacogenetic research.
DRUG ACTIVE/inactive metabolite Cytochrome P450 (CYP) Phase I Glutathione-S-transferases (GST) Phase II INACTIVE metabolite DRUG and XENOBIOTIC METABOLISM
Population stratification in Singapore 70 Indian et al.,2005 Chowbay Chinese Malay 60 50 40 Frequency (%) 30 20 10 0 GSTM1-null CYP3A5*1
GSTM3 (6bp deletion) *A/*A *A/*B 60 *B/*B 40 Genotype frequency (%) 20 0 African-American African Bantu White American Data from Park et al., 2000; Tetlow et al., 2004
GSTM3 (6bp deletion) *A/*A *A/*B 60 *B/*B 40 Genotype frequency (%) 20 0 Black Brazilians African Bantu Portuguese Data from Park et al., 2000; Medeiros et al., 2004; Suarez-Kurtz et al., 2006
GENETIC ADMIXTURE: the mixing of two or more genetically differentiated populations. “Because of considerable genetic admixture in most human populations...” Nebert and Menon, Pharmacogenomics 2001
Sources of the tri-hybrid Brazilian population 1500 ~ 2.5 M Amerindians 1500 - 1808 ~ 0.5 M Portuguese 1851 - 1960 ~ 4.5 M immigrants Portugal 1.7 M Italy 1.6 M Spain 0.7 M Germany 0.25 M Suarez-Kurtz < 1551 - 1880 ~ 3.6 M Enslaved Africans
Parra et al., 2003 African ancestry index 6% 38% 53% Brazilians in southeast rural area
Parra et al., 2003 African ancestry index Brazilians in southeast rural area
Parra et al., 2003 African ancestry index 6% 38% 53% Brazilians in southeast rural area
Suarez-Kurtz et al., Clin Pharm Ther, 2005 based on 40 indel AIM set developed by Sergio D. J. Pena
Self-declared BLACK Brazilians Self-declared WHITE Brazilians European European Amerindian African African Amerindian Pena et al. 2006
GSTM3*B/*B 0.4 0.3 Genotype frequency 0.2 0.1 0.0 < 25 25 - 50 50 -75 >75 White Black African ancestry (%)
African-Caribbeans African-Americans Puerto Ricans Hispanics Mexicans * E. Parra et al., Nat Genet2004
a Jorde & Wooding, Nat Genet 2004, adapted from Bamshad et al., Am J Hum Genet 2003
Jorde & Wooding, Nat Genet 2004, adapted from Bamshad et al., Am J Hum Genet 2003
African European Asian Oceanian Native American Serre & Pääbo, Genome Res 2004
CYP2C19*2 CYP2C19*3 Lamba et al. Clin Pharm Ther2000 Worldwide gradients in CYP2C19 variant allele frequency
FREQUENCY DISTRIBUTION OF CYP2C9*5 Data from Dickman et al.(2001), Xie et al. (2003, and references therein), Llerena et al. (2004).
> G > Glu G/C
92% European 7.5% African 0.5% Amerindian mtDNA L3d Suarez-Kurtz et al. Clin Pharm Ther, 2005
Mother Father
CYP2C9 alleles *5 W I *1 W W I “Race/ethnic” categorization/discrimination: appearance vs. descent