title: Utility of genetic markers in the study of human resemblance.
abstract: A method for the estimation of genetic correlations based upon analysis of genetic marker phenotypes is presented. At a given marker locus, the probability of observing a pair of individuals with a specific combination of phenotypes can be expressed as a function of the gene frequencies at that locus and the genetic correlation (R) between that pair. The likelihood of obtaining a sample of n such pairs with their phenotypes at m marker loci can be expressed as a product of nm such functions. From the likelihood function, maximum likelihood estimates of R can be obtained, and hypotheses about R may be tested. A sample of Swedish twin families (61 dizygotic twin pairs, 268 husband-wife pairs, and 164 sib pairs) were analyzed by this method using information from 21 markers. It was found that for the twin pairs, R = 0.458, which was significantly different from the R calculated for sib pairs (R = 0.558) but not significantly different from the expected 0.5. for the husband-wife pairs, it was found that R = 0.086, which did differ significantly from the expected value of 0, indicating the presence of nonrandom mating in this population.
mesh_terms: D000328:Adult; D005260:Female; D005787:Gene Frequency; D005819:Genetic Markers; D006801:Humans; D008126:Lod Score; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011247:Pregnancy; D014427:Twins; D014429:Twins, Dizygotic
chemical_list: D005819:Genetic Markers