If family has celiac
Persons who have relatives with celiac disease
are more likely to get celiac disease (it's hereditary).
The disease occurs more often in certain ethnic/racial groups because more people in those groups carry the hla-dq2 and hla-dq8 genes that "cause" celiac disease. The genes are more common in persons from northern/western europe, but are uncommon in western pacific rim populations (china/japan).