The effects of genetic screening and assortative mating on lethal recessive-allele frequencies and homozygote incidence.

The widespread use of genetic screening, along with mating and reproductive patterns reflecting that information, can significantly alter the genetic structure of populations. Both allele frequencies and mortality could be significantly reduced if carriers of lethal recessive alleles were withdrawn from the mating pool. But schemes to mask deleterious alleles in heterozygous condition could significantly increase the deleterious-allele frequencies while resulting in only a slight reduction in mortality. The immediate and equilibrium consequences of such mating strategies may be quite disparate.