With regard to diabetes mellitus, which of the following is a gene of major effect?
A. HNF-4 alpha
B. TCF7L2
C. KCNJ11
D. FTO
E. CDKAL1
Answer: A. Mutations in the HNF-1 alpha or HNF-4 alpha genes cause MODY. These are genes of major effect, causing this unusual monogenic form of type 2 diabetes mellitus.
The other genes mentioned in the question are genes of small effect.
See chapter 14 of the book. | 
