Strong genetic component for gluten intolerance disorder

There is a strong genetic component to the gluten intolerance disorder, coeliac disease, shows research in Gut.

In the largest study of its kind, Italian researchers studied 47 twin pairs, who were selected on the basis that one belonged to the Italian Coeliac Disease Association (AIC). They were tested for antibodies specific to coeliac disease to ensure that ‘silent’ disease was detected, and their genetic profile was mapped. Tissue samples were taken to confirm changes indicative of the disease.

There were 20 (monozygotic) identical pairs, six of whom were male and 14 of whom were female, and 27 non-identical (dizygotic) pairs, eight of whom were male, seven of whom were female, and 12 of whom were opposite sex pairs.

Fifteen of the identical and three of the non-identical twins had signs of coeliac disease. All identical twin pairs had genes that predispose to developing the disease (DQ2 or DQ8, or DRB4). Five non-identical pairs carried a ‘risky’ gene, but only one of the five pairs matched. Thirteen non-identical pairs had different genetic patterns that also increased the risk of developing coeliac disease. But this matched in only two pairs.

Being female increased the risk of developing the disease by 30 per cent in a twin who was not affected. And those over the age of 30 were twice as likely to develop the disease. A ‘risky’ gene pattern tripled the risk in the co-twin.

The authors conclude that apart from gluten in the diet, a shared environment has little or no impact on the risk of developing coeliac disease in non-identical twins, and that environmental factors have little influence, overall.

But they suggest that more than one gene may be involved in the development of the disease, and that rather than it being a case of a missing or faulty gene, it is perhaps a series of genetic factors that combine together to produce gluten intolerance.