Indel markers: genetic diversity of 38 polymorphisms in Brazilian populations and application in a paternity investigation with post mortem material

Aiming to evaluate the usefulness of 38 non-coding bi-allelic autosomal indels in genetic identification and kinship testing, three Brazilian population samples were studied: two from Rio de Janeiro (including a sample of individuals with self-declared African ancestry) and one Native American population of Terena from Mato Grosso do Sul. Based on the observed allele frequencies, parameters of forensic relevance were calculated. The combined power of discrimination of the 38 indels was high in all studied groups (PD≥0.9999999999997), although slightly lower in Native Americans. Genetic distance analysis showed significant differences between the allele frequencies in the Rio de Janeiro population and those previously reported for Europeans, Africans and Asians explained by its intermediate position between Europeans and Africans. As expected, the Terena sample was significantly different from all the other populations: Brazilians from Rio de Janeiro general population and with self-declared African ancestry, Europeans, Africans and East Asians. Finally, the performance of the 38-indel multiplex assay was tested in post-mortem material with positive results, supporting the use of short amplicon bi-allelic markers as an additional tool to STR analysis when DNA molecules are degraded.