Mexican mestizo population sub-structure: effects on genetic and forensic statistical parameters

• Published in: Molecular biology reports 2012-12, Vol.39 (12), p.10139-10156
• Main Authors: Noris, Gino, Santana, Carla, Meraz-Ríos, Marco Antonio, de Lourdes Munoz, María, Majluf-Cruz, Abraham, Magaña, Jonathan J., Granados, Julio, Quezada, Rosa, Revilla, María Cristina, Martínez-Salas, Sergio, Xihuitl, Salvador, Martínez de la Escalera, Gonzalo, Díaz-Badillo, Alvaro, Calderon-Aranda, Emma S., Gómez, Rocío
• Format: Article
• Language: English
• Subjects: Animal Anatomy; Animal Biochemistry; Biomedical and Life Sciences; Black People - genetics; Data processing; Forensic Genetics; Forensic science; Forensic sciences; Gene Frequency; Genetic analysis; Genetic diversity; Genetic linkage; Genetic Loci; Genetic markers; Genetic Testing; Genotype; Histology; Homozygotes; Humans; Inbreeding; Indians, North American - genetics; Life Sciences; Linkage Disequilibrium; Mexico; Microsatellite Repeats; Models, Genetic; Models, Statistical; Molecular biology; Morphology; Multiracial people; Paternity; Population; Population genetics; Statistics; White People - genetics
• ISSN: 0301-4851; 1573-4978
• DOI: 10.1007/s11033-012-1888-1

Since Mexican mestizos are an admixed population, it is necessary to determine the effects that the substructure of the population has on genetic and forensic parameters. With this aim, a study was performed with 15 STR loci (CODIS plus D2S1338 and D19S433) on 1,640 unrelated Mexican mestizos. We determine allele and genotypic frequencies observing departure from Hardy–Weinberg expectation (12 out of 15 loci, with an excess of homozygotes, Fis  > 0), as well as pairs of loci in an apparent linkage disequilibrium (13 of 92 loci). We conducted a test for genetic population stratification, the results show that the Mexican mestizo population is substructured into three subgroups, which are in HW and linkage equilibrium. The combination of the 15 loci in the whole population has high forensic efficiency with the capacity to genetically discriminate one individual in one quintillion (1/10 18 ). Our data potentially validates the use of these 15 STR loci to establish forensic identity and parentage testing for legal purposes, and offers a powerful tool for genetic variation analysis. However, given that the population is stratified, we highly recommend applying a correction with the inbreeding coefficient in calculations of paternity and forensic studies to avoid erroneous assumptions.