A young man knows that his grandfather had Huntington disease (genotype Hh). However, his father passed away at the age of 26 wi
thout ever being tested or showing signs of HD. His mother did not have Huntington disease. What is the probability that this young man will develop HD when he is older? A. 1/4
B. 1/2
C. 0
D. 1
The reason that the answer is 1/4 is because the young man, his grandfather, his father, and his mother equal 4 people. The young man is 1 person. 1 person/4 people = 1/4.
