Paternity tests in Mexico: Results obtained in 3005 cases

• Published in: Journal of forensic and legal medicine 2018-04, Vol.55, p.1-7
• Main Authors: García-Aceves, M.E., Romero Rentería, O., Díaz-Navarro, X.X., Rangel-Villalobos, H.
• Format: Article
• Language: English
• Subjects: Chromosomes, Human, Y; Genotype; Homozygote; Human identification; Humans; Male; Mexico; Microsatellite Repeats; Motherless; Mutation; Paternity; Paternity testing; Polymerase Chain Reaction; STRs
• ISSN: 1752-928X; 1878-7487
• DOI: 10.1016/j.jflm.2018.02.003

National and international reports regarding the paternity testing activity scarcely include information from Mexico and other Latin American countries. Therefore, we report different results from the analysis of 3005 paternity cases analyzed during a period of five years in a Mexican paternity testing laboratory. Motherless tests were the most frequent (77.27%), followed by trio cases (20.70%); the remaining 2.04% included different cases of kinship reconstruction. The paternity exclusion rate was 29.58%, higher but into the range reported by the American Association of Blood Banks (average 24.12%). We detected 65 mutations, most of them involving one-step (93.8% and the remaining were two-step mutations (6.2%) thus, we were able to estimate the paternal mutation rate for 17 different STR loci: 0.0018 (95% CI 0.0005–0.0047). Five triallelic patterns and 12 suspected null alleles were detected during this period; however, re-amplification of these samples with a different Human Identification (HID) kit confirmed the homozygous genotypes, which suggests that most of these exclusions actually are one-step mutations. HID kits with ≥20 STRs detected more exclusions, diminishing the rate of inconclusive results with isolated exclusions (