Question

John, age 47, has just been diagnosed with Huntington's disease, which is caused by a rare dominant allele. His daughter, age 25, has a 2-year-old son. No one else in the family has the disease. Without knowing anything about the 25-year-old daughter's genotype, what is the probability that the 2-year-old son will eventually develop the disease?

Answer 1

Answer: 25%

Step-by-step explanation:

John is the one originally diagnosed of having the Huntington’s disease caused by the rear allele gene. No one else in the family has the disease, the genotype of John daughter is unknown. The probability of His daughter having the disease is 50%. The probability that she would be the disease on to johns two years old grand child is 25%.