Question

Huntington's disease is caused by an insertion of extra CAG repeats into the Huntington disease gene. Laboratory technicians at Bulldog Bio Genetic Testing services performed PCR to test two patients for Huntington's disease. Which of the following is true about the results shown?

a) Both patients have a normal number of CAG repeats
b) One patient has an increased number of CAG repeats
c) Both patients will develop Huntington's disease
d) The test cannot determine the CAG repeat count

Answer 1

The PCR test can determine the number of CAG repeats in the Huntington disease gene, indicating whether a patient has an increased number of repeats or a normal number.

Step-by-step explanation:

In Huntington's disease, an insertion of extra CAG repeats into the Huntington disease gene causes the disorder. The results of the PCR test performed by the laboratory technicians at Bulldog Bio Genetic Testing services can determine the CAG repeat count, indicating whether a patient has an increased number of CAG repeats or a normal number of repeats. Therefore, the correct answer is b) One patient has an increased number of CAG repeats.