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Klein, T.

Publications and source records attributed to Klein, T..

2 recordsLinked to original sources

Standardized biogeographic grouping system for annotating populations in pharmacogenetic research

The varying frequencies of pharmacogenetic alleles between populations have important implications for the impact of these alleles in different populations. Current population grouping methods to communicate these patterns are insufficient as they are inconsistent and fail to reflect the global distribution of genetic variability. To facilitate and standardize the reporting of variability in pharmacogenetic allele frequencies, we present seven geographically-defined groups: American, Central/South Asian, East Asian, European, Near Eastern, Oceanian, and Sub-Saharan African, and two admixed groups: African American/Afro-Caribbean and Latino. These nine groups are defined by global autosomal genetic structure and based on data from large-scale sequencing initiatives. We recognize that broadly grouping global populations is an oversimplification of human diversity and does not capture complex social and cultural identity. However, these groups meet a key need in pharmacogenetics research by enabling consistent communication of the scale of variability in global allele frequencies and are now used by PharmGKB.

genetics

Long term context dependent genetic adaptation of the viral genetic cloud

RNA viruses generate a cloud of genetic variants within each host. This cloud contains high frequency genotypes, and a very large number of rare variants. While the dynamics of frequent variants are affected by the fitness of each variant, the rare variants cloud is affected by more complex genetic factors, including context dependent mutations. It serves as a spearhead for the viral populations movement within the adaptive landscape. We here use an experimental evolution system to show that the genetic cloud surrounding the Coxsackie virus master sequence slowly, but steadily, evolves over hundreds of generations. The evolution of the rare variants cloud often precedes the appearance of high frequency variants. The rare variants clouds evolution is driven by a combination of a context-dependent mutation pattern and selection for and against specific nucleotide compositions.This combination affects the mutated dinucleotide distribution, and eventually leads to a non-uniform dinucleotide distribution in the main viral sequence. We then tested these conclusions on other RNA viruses with similar conclusions.

genetics