Question

6. Students are analyzing two datasets. In one dataset, patients with two different mutations show higher LDL levels than patients with only one mutation. In another dataset, patients with no LDLR, PCSK9, or APOB mutations still show high cholesterol, and their polygenic risk scores are also high.

Which conclusions are supported by the evidence?
(Select all that apply)

Responses

A. Having mutations in more than one gene can increase cholesterol levels more than just one mutation.


B. Polygenic risk scores explain how many small-effect variants together raise disease risk.


C. Patients without mutations in LDLR, PCSK9, or APOB cannot have high cholesterol.


D. More than one gene can work together to affect cholesterol levels.


E. All cases of high cholesterol are caused by diet and environment alone.

Answer 1

Correct choices: A, B, and D.

- A is supported: the first dataset shows patients with mutations in two different genes have higher LDL than those with only one mutation, so multiple mutations can increase levels beyond a single mutation.
- D is supported: that same result indicates more than one gene can act together (additively or interactively) to affect cholesterol.
- B is supported: the second dataset (high cholesterol without LDLR/PCSK9/APOB mutations but with high polygenic risk scores) shows that many small-effect variants combined (a polygenic score) can explain elevated risk.

C and E are not supported:
- C is contradicted by the second dataset (patients without those mutations still had high cholesterol).
- E is false because genetic explanations (monogenic and polygenic) — not only diet/environment — account for some cases.