Huntington's disease tends to strike earlier and lead to a more rapid progression of symptoms as it moves from generation to generation. Also, it tends to strike earlier and progress more rapidly when it is passed from the father to his children rather than from the mother. Which genetic phenomenon (or phenomena) is/are likely operating here? (Select all that apply.)
A) incomplete penetrance
B) sex-limited inheritance
C) genetic anticipation
D) parental imprinting
E) epistasis

Question

Quizplus · Accepted Answer

Genetic anticipation and parental imprinting are both genetic phenomena that can lead to the earlier onset and more rapid progression of Huntington's disease. Genetic anticipation is a phenomenon in which the symptoms of a genetic disorder become more severe and appear earlier in each successive generation. Parental imprinting is a phenomenon in which the expression of a gene depends on whether it was inherited from the mother or the father. In the case of Huntington's disease, the gene that causes the disorder is located on the X chromosome, and it is more likely to be expressed when it is inherited from the father than from the mother.

Huntington's Disease Tends to Strike Earlier and Lead to a More