The purpose of this excel workbook is to compare several methods for calculating allele frequencies for ABO blood groups. The methods used are the standard textbook approach, the quadratic formula, and the EM algorithm. The user enters the observed numbers of each phenotype. The workbook then uses these to calculate estimates of allele frequencies in Hardy-Weinberg equilibrium for each method. The user can view the formulas used to calculate frequencies through informational buttons. Four forms of graphical output are used to compare each method. Output includes histograms of chi-square values and observed vs. expected phenotype frequencies, as well as a ternary plot of the allele frequencies for each method. Users can also examine a dataset of blood group frequencies for different ethnic groups from Bloodbook.com.

Hardy-Weinberg Equilibrium

Boyer, S H, IV, 1963 Papers on Human Genetics. Englewood Cliffs, NJ: Prentice-Hall.

Hardy, G. H., 1908 Mendelian proportions in a mixed population. Science 28:49-50.

Weinberg, W., 1908 Über den Nachweis der Vererbung beim Menschen. Jahresh. Wuertt. Ver. vaterl. Natkd. 64:369-382.

Snustad D P, Simmons M J (2003) Principles of Genetics. 3rd Edition. New York : John Wiley & Sons, Inc.

Li C C (1955) Population Genetics. Chicago : University of Chicago Press.

Crow J F (1986) Basic Concepts in Population, Quantitative, and Evolutionary Genetics. New York : W. H. Freeman and Company.

Wellek S, 2004 Tests for establishing compatibility of an observed genotype distribution with Hardy-Weinberg Equilibrium in the case of a biallelic locus. Biometrics 60: 694-703.

Hosking L, Lumsden S, Lewis K, Yeo A, McCarthy L, Bansal A, Riley J, Purvis I, Xu CF, 2004 Detection of genotyping errors by Hardy-Weinberg equilibrium testing. European Journal of Human Genetics 12: 395-9.

Wittke-Thompson JK, Pluzhnikov A, Cox NJ, 2005 Rational inferences about departures from Hardy-Weinberg equilibrium. American Journal of Genetics 76: 967-86.

Genes, Environment, and Human Behavior. Biological Sciences Curriculum Study

Racial & Ethnic Distribution of ABO Blood Types by BLOODBOOK.COM

The Hardy-Weinberg Equilibrium by John W. Kimball

What is a maximum likelihood estimate? by Kent Holsinger

ABO Allele Frequencies by Robert J. Huskey