Question

A cytogenetics laboratory report states that a patient has a deletion of a chromosome distal to 5p15.31. Which of the following best describes what this means?

(A) There is a deletion of a portion of the long arm of chromosome 5 with the breakpoint at band p15.31.
(B) There is a deletion of a portion of the short arm of chromosome 5 with the breakpoint at band p15.31.
(C) There is a deletion of a portion of the long arm of chromosome 15 at band 5p31.
(D) There is a deletion of a portion of the short arm of chromosome 15 at band 5p31.

Answer 1

The correct answer is (A) There is a deletion of a portion of the long arm of chromosome 5 with the breakpoint at band p15.31.

Step-by-step explanation:

The term "distal" in cytogenetics refers to the end of a chromosome opposite to the centromere. In this case, a deletion of a chromosome distal to 5p15.31 means that there is a deletion of a portion of the long arm of chromosome 5 with the breakpoint at band p15.31. Therefore, option (A) is the correct answer.