Genotype frequency

A De Finetti diagram visualizing genotype frequencies as distances to triangle edges x (AA), y (Aa) and z (aa) in a ternary plot. The curved line are the Hardy–Weinberg equilibria.
A Punnett square visualizing the genotype frequencies of a Hardy–Weinberg equilibrium as areas of a square. p (A) and q (a) are the allele frequencies.

Genetic variation in populations can be analyzed and quantified by the frequency of alleles. Two fundamental calculations are central to population genetics: allele frequencies and genotype frequencies.[1] Genotype frequency in a population is the number of individuals with a given genotype divided by the total number of individuals in the population.[2] In population genetics, the genotype frequency is the frequency or proportion (i.e., 0 < f < 1) of genotypes in a population.

Although allele and genotype frequencies are related, it is important to clearly distinguish them.

Genotype frequency may also be used in the future (for "genomic profiling") to predict someone's having a disease[3] or even a birth defect.[4] It can also be used to determine ethnic diversity.

Genotype frequencies may be represented by a De Finetti diagram.

  1. ^ Brooker R, Widmaier E, Graham L, and Stiling P. Biology (2011): p. 492
  2. ^ Brooker R, Widmaier E, Graham L, and Stiling P. Biology (2011): p. G-14
  3. ^ Janssens; et al. "Genomic profiling: the critical importance of genotype frequency". PHG Foundation.
  4. ^ Shields; et al. (1999). "Neural Tube Defects: an Evaluation of Genetic Risk". American Journal of Human Genetics. 64 (4): 1045–1055. doi:10.1086/302310. PMC 1377828. PMID 10090889.