Huntington disease is a neurodegenerative genetic disorder that typically manifests itself around age 40.A 25-year-old woman comes to your genetic counseling center because she knows that Huntington disease occurs in members of her father's family.Her paternal grandfather was afflicted,but so far her 50-year-old father shows no symptoms.Her two great-great grandmothers on her father's side were healthy well into their 90s,but one of her great-great grandfathers died of unknown causes at 45.Testing for Huntington disease is extremely expensive,but she is concerned that she may fall victim to this disease and wants to plan her life accordingly.After examining her pedigree you advise her to
A)get tested because there is no possibility that she is homozygous.
B)not get tested because only males in her family get the disease.
C)get tested because her father could be a carrier.
D)not get tested because her father is only a carrier and it is very unlikely her mother is a carrier.
E)not get tested because her 50-year-old father shows no symptoms.

Question

Quizplus · Accepted Answer

Huntington's disease is an autosomal dominant disorder, meaning that only one copy of the defective gene, inherited from either parent, is sufficient to cause the disease. The woman's concern is valid because her father, despite not showing symptoms, could still be a carrier of the gene mutation. Since the disease can manifest later in life, the fact that her father is currently asymptomatic does not eliminate the possibility of him being a carrier. Therefore, she could have inherited the gene and might develop the disease later.

Huntington Disease Is a Neurodegenerative Genetic Disorder That Typically Manifests