Celiac Disease (CD)is a Common, Usually Inherited Human Disorder of Intestinal

Multiple Choice

Celiac disease (CD) is a common, usually inherited human disorder of intestinal inflammation that is triggered by eating gluten, a major protein in wheat and other cereal grains. It is the most frequent food intolerance. One of the three genes involved is for SH2B3, a protein involved in innate, nonspecific immune response to bacterial pathogens. Celiac sufferers frequently have a particular allele of this gene. It is so common that which of the following might be hypothesized?

A) The gene must be common to all primate genomes.
B) The gene must be common in most mammalian genomes.
C) The allele must have been positively selected for during a period of especially frequent bacterial infections.
D) The wild-type allele must have been selected against during periods of frequent bacterial infections.
E) The gene must code for a T-cell receptor for a common bacterial component.