DefinitionThis section has been translated automatically.
Term used in genetics. Allele that forms a phenotype that indirectly causes disease or death. An example of this is cystic fibrosis. It is rare for these alleles to actually develop the lethal phenotype, i.e. the fatal phenotype; the individuals usually die at an early embryonic stage.
Lethal alleles are almost always recessive and therefore only become active in homozygosity.
