Practice question

Autosomal recessive trait manifests phenotypically only in homozygous recessive genotype, heterozygous carriers remain healthy due to sufficient normal gene product. Carriers allow allele to pass silently through generations without appearance, leading to affected child appearing after unsuspected carrier parents mate. This creates apparent skipping of generations in pedigree, with affected individuals often clustered horizontally among sibs. This pattern contrasts with dominant traits appearing vertically each generation. Recessive pedigrees may also show increased consanguinity because relatives share carrier allele more frequently than random individuals.