High frequency of the DRD2/ANKK1 A1 allele in Mexican Native Amerindians and Mestizos and its association with alcohol consumption.
Mexico has an ancient tradition of alcohol drinking influenced by genetic and sociocultural factors. This study aimed to determine the distribution of the DRD2/ANKK1 TaqIA polymorphism in Mexican populations and to analyze its association with heavy drinking.



In a cross-sectional and analytical study, 680 unrelated subjects including two Native Amerindians groups (87 Nahuas and 139 Huicholes), and two Mestizos groups (158 subjects from Tepic, Nayarit and 296 subjects from Guadalajara, Jalisco) were enrolled. DRD2/ANKK1 genotyping was performed by PCR-RFLP and allelic discrimination assays. Genetic analyses were conducted by Arlequin and Structure software. Heavy drinking was defined as ≥300g alcohol/week. The association of the DRD2/ANKK1 TaqIA polymorphism with heavy drinking was estimated.



Heavy drinking was prevalent in 64.7% of the study population. The DRD2/ANKK1 A1 allele prevailed in 67% and 65% of Nahuas and Huicholes, respectively and 51% and 47.3% in Mestizos from Tepic and Guadalajara, respectively. Heavy drinking was associated with the A1A1 genotype in the Mestizos of Guadalajara (A1A1 vs. A1A2 OR=4.79, 95%CI 1.81-12.68, p=0.0006; A1A1 vs. A1A2+A2A2, OR=4.09, 95%CI 1.56-10.68, p=0.0021) and in the Mestizos from Tepic (A1A1 vs. A1A2, OR=5.92, 95%CI 2.12-16.49, p=0.0002); A2A2, OR=14.56, 95%CI 3.57-59.24, p=0.00004); A1A2+A2A2, OR=6.68, 95%CI 2.42-18.42, p=0.00005). In Native Amerindians, a lack of association was found.



High frequencies of the DRD2/ANKK1 A1 allele were present in Mexican populations. Native Amerindians exhibited the highest frequencies of the A1 allele documented worldwide to date. The A1A1 genotype was associated with heavy drinking in Mestizos.
Department of Molecular Biology in Medicine, Civil Hospital of Guadalajara, "Fray Antonio Alcalde," Guadalajara, Jalisco, Mexico; Health Sciences Center, University of Guadalajara, Guadalajara, Jalisco, Mexico. Electronic address: apanduro@prodigy.net.mx.
Arturo
A
Panduro
Department of Molecular Biology in Medicine, Civil Hospital of Guadalajara, "Fray Antonio Alcalde," Guadalajara, Jalisco, Mexico; Health Sciences Center, University of Guadalajara, Guadalajara, Jalisco, Mexico.
Omar
O
Ramos-Lopez
Center for the Study of Alcoholism and Addictions, Guadalajara, Jalisco, Mexico; Health Sciences Center, University of Guadalajara, Guadalajara, Jalisco, Mexico.
Octavio
O
Campollo
Department of Molecular Biology in Medicine, Civil Hospital of Guadalajara, "Fray Antonio Alcalde," Guadalajara, Jalisco, Mexico; Health Sciences Center, University of Guadalajara, Guadalajara, Jalisco, Mexico.
Eloy Alfonso
EA
Zepeda-Carrillo
Department of Molecular Biology in Medicine, Civil Hospital of Guadalajara, "Fray Antonio Alcalde," Guadalajara, Jalisco, Mexico; Health Sciences Center, University of Guadalajara, Guadalajara, Jalisco, Mexico.
Karina
K
Gonzalez-Aldaco
Department of Molecular Biology in Medicine, Civil Hospital of Guadalajara, "Fray Antonio Alcalde," Guadalajara, Jalisco, Mexico; Health Sciences Center, University of Guadalajara, Guadalajara, Jalisco, Mexico.
Rafael
R
Torres-Valadez
Department of Molecular Biology in Medicine, Civil Hospital of Guadalajara, "Fray Antonio Alcalde," Guadalajara, Jalisco, Mexico; Health Sciences Center, University of Guadalajara, Guadalajara, Jalisco, Mexico.
Sonia
S
Roman
D000328:Adult; D000428:Alcohol Drinking / Q000235:genetics*; D000437:Alcoholism / Q000453:epidemiology / Q000235:genetics; D003430:Cross-Sectional Studies; D005006:Ethnicity; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data*; D008111:Liver Function Tests; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D014481:United States / Q000453:epidemiology
C581293:DRD2 protein, human; D017448:Receptors, Dopamine D2; C489948:ANKK1 protein, human; D017346:Protein Serine-Threonine Kinases
Alcohol consumption; DRD2/ANKK1; Dopamine D2 receptor; Mexico; Native Amerindians