Q: We have an 18 month old son with Down syndrome [DS] who we think is doing well. We read a recommendation on a DS website that all children with DS be screened for celiac disease. Our pediatrician is unsure this recommendation makes sense. Should we do this, and if so, how is it done?A: Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food. Children [or adults] who have celiac disease [CD] cannot tolerate a protein called gluten [found in wheat, rye and barley]. When people with CD eat foods or use products containing gluten, their immune system responds by damaging the small intestine, and they become malnourished due to the poor absorption of nutrients. CD is a genetic disease, meaning it runs in families, and can be triggered at any point in the lifespan. CD may be triggered – or become active for the first time – by the introduction of gluten to the diet [typically around 1-2 years of age] or by such diverse events as surgery, pregnancy, viral infection, or severe emotional distress.
There are basically 3 steps necessary for a child to develop CD. First, they need the genetic makeup that makes them susceptible to this disease. Second, the child needs to be exposed to gluten. Third, the “trigger” must occur that allows the immune response to damage the small intestine lining. CD affects people differently. The most common symptoms in childhood include failure to grow, weight loss, excessive gas, recurrent abdominal bloating and pain, and chronic diarrhea, and irritability.
So why is this disease of interest to the DS community? It appears from studies done in the last decade that people with DS are at higher risk to develop CD than the general population. In the United States the general population has between 0.5-1.0% risk of developing CD, while various studies have found a 4-7% risk for children with DS. With our understanding of the increased risk for children with DS, a good deal of discussion is taking place nationally regarding the wisdom of screening all DS children for CD at age 2 years. At this time there is no clear cut recommendation and a number of studies are ongoing.
One of the major problems making the screening recommendation difficult is the difficulty in making the diagnosis of CD. The only absolute way to diagnose CD is through a small bowel biopsy. In children this requires anesthesia and direct endoscopy. Since such a procedure is invasive, expensive, and carries some risk, it is not in the best interest of the child or family to do a biopsy on every child with DS. Recently, research has shown that children with CD have higher than normal levels of certain autoantibodies in their blood. These antibodies can be measured with a simple blood test. Unfortunately these tests are difficult to perform in the laboratory and difficult to interpret. They do, however, give us a reasonable device to identify those patients who should have an intestinal biopsy. The currently recommended tests for this screening include:
Immunoglobulin A [IgA]
anti-tissue transglutaminase [tTGA]
IgA anti-endomysium antibodies [AEA]
Until we resolve the controversial issue of routine screening, I certainly recommend testing all DS children who have any of the clinical signs and symptoms of CD. As CD is a very difficult disease to diagnose and the symptoms overlap with many other medical conditions [irritable bowel syndrome, Crohn’s disease, iron-deficiency anemia, intestinal infections, and many more], don’t hesitate if CD is one of the possibilities.
Treatment of CD is simple to prescribe and very difficult for children and families to follow…the complete avoidance of gluten. A gluten-free diet includes eliminating all wheat, rye and barley, as well as the many products that have gluten as an ingredient [read a few labels and you will see how prevalent this nutrient is in most of our diets]. I would only start such a diet with the help of a registered dietician
