A putative father in paternity case is homozygous for allele 23 of the D21S11 gene. The frequency of allele 23 is 0.1. A child is born with a nonmaternal 23 allele at its D21S11 gene. What is the Paternity Index (PI) for this putative father in this case?

Question

Quizplus · Accepted Answer

The Paternity Index (PI) is calculated as the probability of the child inheriting the allele from the putative father divided by the probability of the child inheriting the allele from a random man in the population. Since the putative father is homozygous for allele 23, the probability of him passing this allele to the child is 1. The frequency of allele 23 in the population is 0.1, so the probability of a random man passing this allele is 0.1. Therefore, the PI is 1 / 0.1 = 10.

A Putative Father in Paternity Case Is Homozygous for Allele