Estimas de los niveles de autozigosis en el hombre basadas en registros históricos y análisis genómicos. Retos y oportunidades de la tecnología molecular de alta resolución

Resumen

From the second half of 19th century onwards, population genetics has attempted to explain through theoretical models, concepts and empirical data, the evolutionary consequences and biological cost of mating between relatives. The genetic load linked to the consanguineous marriages has been traditionally assessed from pedigree reconstruction and identity of surnames of both members of the couple as a reflection of a potential biological relationship (isonymy method). These kind of results are being enriched by molecular approaches based on new high-resolution analyses of the human genome. The present survey provide chronological comparisons among those strategies used for estimating human autozygosity. Inbreeding estimates based on pedigrees and genomic data show a rather positive correlation, mainly in populations considered as human isolates. The implementation of isonymy methodologies entail limitations that generate overrated inbreeding estimates. Genomic studies have described autozygous chromosomal segments, known as Runs of Homozygosity (ROHs). Analyses of these tracts allow not only assessments of recent kinship structure of populations but also a better knowledge of human demographic dynamics in an evolutionary perspective. Furthermore, ROHs can be analyzed in any population, not being restricted to those ones defined by a low demographic size. In conclusion, the current genomic approach aimed to evaluate human inbreeding provides an interesting, promising challenge regarding other traditional methodologies based on historical records.