TY - JOUR
T1 - Recombinatioin of haplotypes leads to biased estimates of admixture proportions in human populations
AU - Chakraborty, R.
AU - Smouse, P. E.
PY - 1988
Y1 - 1988
N2 - A population formed by genetic admixture of two or more source populations may exhibit considerable linkage disequilibrium between genetic loci. In the presence of recombination, this linkage disequilibrium declines with time, a fact that is often ignored when considering haplotypes of closely linked systems [e.g., Gm serum group (gamma globulins), HLA, and, more recently, restriction fragment length polymorphisms]. Recombination alters haplotype frequencies over time, and the haplotype-derived measures of admixture proportions from haplotype frequencies in generations following the admixture event become progressively more biased. The direction and extent of this bias can be predicted only when the history of admixture is known. Numerical illustration suggests that this bias is problematic whenever rt > 0.05, where r is the recombination rate between linked loci and t is the time (in generations) that has elapsed since the admixture event. In general, even the haplotype frequencies defined by multiple restriction fragment length polymorphisms should be used with caution for admixture analysis. When recombination rates or the time since admixture are not precisely known, it is advantageous to consider each restriction fragment length polymorphism site separately for admixture analysis.
AB - A population formed by genetic admixture of two or more source populations may exhibit considerable linkage disequilibrium between genetic loci. In the presence of recombination, this linkage disequilibrium declines with time, a fact that is often ignored when considering haplotypes of closely linked systems [e.g., Gm serum group (gamma globulins), HLA, and, more recently, restriction fragment length polymorphisms]. Recombination alters haplotype frequencies over time, and the haplotype-derived measures of admixture proportions from haplotype frequencies in generations following the admixture event become progressively more biased. The direction and extent of this bias can be predicted only when the history of admixture is known. Numerical illustration suggests that this bias is problematic whenever rt > 0.05, where r is the recombination rate between linked loci and t is the time (in generations) that has elapsed since the admixture event. In general, even the haplotype frequencies defined by multiple restriction fragment length polymorphisms should be used with caution for admixture analysis. When recombination rates or the time since admixture are not precisely known, it is advantageous to consider each restriction fragment length polymorphism site separately for admixture analysis.
UR - http://www.scopus.com/inward/record.url?scp=0024007039&partnerID=8YFLogxK
U2 - 10.1073/pnas.85.9.3071
DO - 10.1073/pnas.85.9.3071
M3 - Article
C2 - 3362862
AN - SCOPUS:0024007039
SN - 0027-8424
VL - 85
SP - 3071
EP - 3074
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 9
ER -