Report of three cases of congenital sucrase-isomaltase deficiency in children

Objectives To investigate the diagnosis and therapy of congenital sucrase-isomaltase deficiency in children. Methods The characteristics of clinical manifestation,diagnosis and effects of the therapy of three congenital sucrase-isomaltase deficiency cases were summarized. Results In three children, aged 16 months to 19 months, the bowel movement was normal during breast feeding after birth, diarrhea began when weaning breast milk and fed on rice paste or rice porridge, the stool was yellow and watery-like or loose, 7-10 times a day. Physical examinations from the three children showed mild to moderate protein-energy malnutrition. Sucrose challenge tests showed the highest promoted postprandial blood glucose values compared with the fasting blood-glucose were 0.1 (2.0%), 0.1 (2.6%) and 0.9 (19.1%) mmol·L-1, respectively. All of the three children had yellow and watery-like stool 2-4 hours after the sucrose challenge tests. Compared with the fasting blood-glucose, glucose challenge tests showed the highest promoted postprandial blood glucose values were 1.5 (30.6%), 2.3 (65.7%) and 4.4 (107%) mmol·L-1, respectively. Nobody had diarrhea after the glucose challenge tests. When the three children got diagnosed, food containing sucrose and starch was stopped. One to two days after feeding with paste made of soybean and pork, the stool turned to be normal. Three cases had been misdiagnosed as long as 9 to 12 months. Congenital sucrase-isomaltase deficiency was easy to be misdiagnosed as lactose intolerence and milk-protein allergy, but lactose free formula and free amino acid formula could not improve the diarrhea respectively. It also should be differentiate with celiac disease, crohn's disease, intestinal parasitosis,lymphoma and lymphosarcoma. Follow-up: The first case could tolerate small quantity rice and noodle when he was 3 years and 4 months old, and he could tolerate normal dose rice and noodle when he was 4 years and 4 months old. He still could not tolerate sucrose. The second case could tolerate small quantity rice and noodle when he was 3 years old . The third case could not tolerate rice and noodle till now (2 years and 1 month old). Conclusions When congenital sucrase-isomaltase deficiency is suspected, the diagnosis can be made according to the classic history (diarrhea began after weaning the breast milk, the diarrhea can rapidly recovered after avoiding food containing sucrose and starch, along with a positive sucrose challenge test).