Geographic stratification of linkage disequilibrium: a worldwide population study in a region of chromosome 22.
Hum Genomics
; 1(6): 399-409, 2004 Nov.
Article
in En
| MEDLINE
| ID: mdl-15606995
ABSTRACT
Recent studies of haplotype diversity in a number of genomic regions have suggested that long stretches of DNA are preserved in the same chromosome, with little evidence of recombination events. The knowledge of the extent and strength of these haplotypes could become a powerful tool for future genetic analysis of complex traits. Different patterns of linkage disequilibrium (LD) have been found when comparing individuals of African and European descent, but there is scarce knowledge about the worldwide population stratification. Thus, the study of haplotype composition and the pattern of LD from a global perspective are relevant for elucidating their geographical stratification, as it may have implications in the future analysis of complex traits. We have typed 12 single nucleotide polymorphisms in a chromosome 22 region--previously described as having high LD levels in European populations--in 39 different world populations. Haplotype structure has a clear continental structure with marked heterogeneity within some continents (Africa, America). The pattern of LD among neighbouring markers exhibits a strong clustering of all East Asian populations on the one hand and of Western Eurasian populations (including Europe) on the other, revealing only two major LD patterns, but with some very specific outliers due to specific demographic histories. Moreover, it should be taken into account that African populations are highly heterogeneous. The present results support the existence of a wide (but not total) communality in LD patterns in human populations from different continental regions, despite differences in their demographic histories, as population factors seem to be less relevant compared with genomic forces in shaping the patterns of LD.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Chromosomes, Human, Pair 22
/
Linkage Disequilibrium
/
Polymorphism, Single Nucleotide
/
Genetics, Population
Type of study:
Prognostic_studies
Limits:
Humans
Country/Region as subject:
Asia
/
Europa
Language:
En
Journal:
Hum Genomics
Journal subject:
GENETICA
Year:
2004
Document type:
Article
Affiliation country:
Spain