title: Amerindians show no association of PPAR-γ2 gene Ala12 allele and obesity: an "unthrifty" variant population genetics.
abstract: Obesity is for many scholars the most important starting status that gives rise to Metabolic Syndrome (MS) and Type 2 Diabetes (T2D). In the present paper, a genetically homogeneous Amerindian population, as defined by HLA genes, has been genotyped for one of the MS and T2D predisposing genes: PPAR-γ Ala12 and Pro 12 variants. Ala12 has been negatively associated with obesity, but other authors do not find such an association. Notwithstanding, a meta-analysis that used many subjects clearly demonstrated that PPAR-γ Ala12 bearing ones had a reduced risk for T2D. Our results show that Amerindians do not have association of PPAR-γ2 Ala12 and obesity; the latter was measured by waist circumference values after taken specific Amerindian normal waist parameters. Also, a population genetics study indicates that Pro12 allele was the wild allele, which must have occurred before modern humans left Africa. Ala12 may have appeared in Caucasoids later on, according to our comparisons. Negroids tend to show low or null Ala 12 allele frequencies, while most other populations have a significant frequency, particularly European Caucasoids. This may suggest that appearance of Ala12 allele occurred after populations adapted to an agricultural feeding.
authors.affiliation: Departamento de Inmunología, Facultad de Medicina, The Madrid Regional Blood Center, University Complutense, Pabellón 5, Planta 4. Avda. Complutense s/n, 28040, Madrid, Spain. aarnaiz@med.ucm.es
authors.forename: Antonio
authors.initials: A
authors.lastname: Arnaiz-Villena
authors.forename: Mercedes
authors.initials: M
authors.lastname: Fernández-Honrado
authors.forename: Cristina
authors.initials: C
authors.lastname: Areces
authors.forename: Mercedes
authors.initials: M
authors.lastname: Enríquez-de-Salamanca
authors.forename: Sedeka
authors.initials: S
authors.lastname: Abd-El-Fatah-Khalil
authors.forename: Carmen
authors.initials: C
authors.lastname: Coca
authors.forename: Ignacio
authors.initials: I
authors.lastname: Arribas
authors.forename: Manuel
authors.initials: M
authors.lastname: Algora
authors.forename: Diego
authors.initials: D
authors.lastname: Rey
mesh_terms: D000328:Adult; D000368:Aged; D000409:Alanine / Q000235:genetics; D019943:Amino Acid Substitution; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D007199:Indians, South American; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000208:ethnology* / Q000235:genetics*; D047495:PPAR gamma / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D013030:Spain; D055815:Young Adult
chemical_list: D047495:PPAR gamma; D000409:Alanine