(Solved): Part I: John and his mother both have brachydactyly. John and his father both have Huntington disea ...

Part I: John and his mother both have brachydactyly. John and his father both have Huntington disease. Both traits are rare and autosomal dominant. John's wife is phenotypically normal and is pregnant. Two-thirds of people who inherit the Huntington allele show symptoms by age 50 , and brachydactyly is \( 90 \% \) penetrant. What is the probability that the child will express both brachydactyly and Huntington disease by age 50 if two genes are 10 m.u. apart? Write your answer in decimal.