The relationship between homozygosity and the frequency of the most frequent allele
2008 (English)In: Genetics, ISSN 0016-6731, E-ISSN 1943-2631, Vol. 179, no 4, 2027-2036 p.Article in journal (Refereed) Published
Homozygosity is a commonly used summary of allele-frequencydistributions at polymorphic loci. Because high-frequency allelescontribute disproportionately to the homozygosity of a locus,it often occurs that most homozygotes are homozygous for themost frequent allele. To assess the relationship between homozygosityand the highest allele frequency at a locus, for a given homozygosityvalue, we determine the lower and upper bounds on the frequencyof the most frequent allele. These bounds suggest tight constraintson the frequency of the most frequent allele as a function ofhomozygosity, differing by at most and having an average difference of – 2/18 0.1184. The close connection between homozygosityand the frequency of the most frequent allele—which weillustrate using allele frequencies from human populations—hasthe consequence that when one of these two quantities is known,considerable information is available about the other quantity.This relationship also explains the similar performance of statisticaltests of population-genetic models that rely on homozygosityand those that rely on the frequency of the most frequent allele,and it provides a basis for understanding the utility of extendedhomozygosity statistics in identifying haplotypes that havebeen elevated to high frequency as a result of positive selection.
Place, publisher, year, edition, pages
2008. Vol. 179, no 4, 2027-2036 p.
IdentifiersURN: urn:nbn:se:uu:diva-106380DOI: 10.1534/genetics.107.084772OAI: oai:DiVA.org:uu-106380DiVA: diva2:224743