Which Is True for a Twenty-Year-Old Woman with a Gene

Multiple Choice

Which is true for a twenty-year-old woman with a gene for Huntington's disease?

A) It is likely that symptoms of Huntington's disease have already started to appear.
B) It is likely that symptoms of Huntington's disease appeared in childhood and have since faded.
C) She will probably be stricken with Huntington's disease before her 25^th birthday.
D) She is most likely to develop symptoms of Huntington's disease by middle age.