title: Letter: Elderly fathers and the frequency of recessive conditions.
mesh_terms: D000367:Age Factors; D002869:Chromosome Aberrations / Q000453:epidemiology*; D025063:Chromosome Disorders; D005808:Genes, Recessive; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D010290:Parents