Question

What does a double horizontal line between two symbols in a pedigree chart represent?

Options

• Multiple pregnancies

• Adoption of a child

• Consanguineous mating (mating between relatives)

• Divorce or separation

Answer 1

A double horizontal line between two symbols represents consanguineous mating, which is mating between relatives. This notation is important in pedigree analysis because consanguineous matings increase the likelihood of homozygous recessive conditions appearing in offspring, as both parents are more likely to carry the same recessive alleles.