Proportionally more deleterious genetic variation in European than in African populations.
Nature
; 451(7181): 994-7, 2008 Feb 21.
Article
em En
| MEDLINE
| ID: mdl-18288194
ABSTRACT
Quantifying the number of deleterious mutations per diploid human genome is of crucial concern to both evolutionary and medical geneticists. Here we combine genome-wide polymorphism data from PCR-based exon resequencing, comparative genomic data across mammalian species, and protein structure predictions to estimate the number of functionally consequential single-nucleotide polymorphisms (SNPs) carried by each of 15 African American (AA) and 20 European American (EA) individuals. We find that AAs show significantly higher levels of nucleotide heterozygosity than do EAs for all categories of functional SNPs considered, including synonymous, non-synonymous, predicted 'benign', predicted 'possibly damaging' and predicted 'probably damaging' SNPs. This result is wholly consistent with previous work showing higher overall levels of nucleotide variation in African populations than in Europeans. EA individuals, in contrast, have significantly more genotypes homozygous for the derived allele at synonymous and non-synonymous SNPs and for the damaging allele at 'probably damaging' SNPs than AAs do. For SNPs segregating only in one population or the other, the proportion of non-synonymous SNPs is significantly higher in the EA sample (55.4%) than in the AA sample (47.0%; P < 2.3 x 10(-37)). We observe a similar proportional excess of SNPs that are inferred to be 'probably damaging' (15.9% in EA; 12.1% in AA; P < 3.3 x 10(-11)). Using extensive simulations, we show that this excess proportion of segregating damaging alleles in Europeans is probably a consequence of a bottleneck that Europeans experienced at about the time of the migration out of Africa.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Genoma Humano
/
Polimorfismo de Nucleotídeo Único
Limite:
Humans
País/Região como assunto:
Africa
/
America do norte
/
Europa
Idioma:
En
Revista:
Nature
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Estados Unidos