Four Mutations in the SI Gene Are Responsible for the Majority of Clinical Symptoms of CSID

Abstract

nucleotide alterations. Nucleotide numbering used the A of the ATG translation initiation start site as nucleotide þ1.

Clinical Aspects and Treatment of Congenital Sucrase‐Isomaltase Deficiency

“…One patient in the cohort studies by Scott et al appeared to have normal wild-type genes on both alleles with moderately reduced sucrase activity and symptoms provoked by sucrose consumption, which suggested acquired sucrase deficiency even in the presence of normal small intestinal morphology (4). Other causes of false-positive results come from biopsies taken in the proximal duodenum, where disaccharidase levels are often only approximately two-thirds of the levels found in the proximal jejunum (35).…”

Congenital sucrase–isomaltase deficiency: identification of a common Inuit founder mutation

“…16 In people of European descent, 4 mutations account for most disease alleles. 17 We sought to identify a common mutation for congenital sucrase-isomaltase deficiency in the Inuit population.…”

“…Nonetheless, reports of gastrointestinal symptoms in small numbers of people with only a single identifiable SI mutation do raise the question of whether carriers may have mild symptoms when exposed to sucrose. 17,23 The availability of a noninvasive (molecular) test for congenital sucrase-isomaltase deficiency raises the possibility of a more systematic study of the phenotype, if any, in heterozygous people.…”

Use of the Biphasic13C-Sucrose/Glucose Breath Test to Assess Sucrose Maldigestion in Adults with Functional Bowel Disorders

“…This study's outcome is higher than the frequency of known sucrase mutations, and our findings suggest that the sucrose intolerance may be acquired or that epigenetic factors may be in play. This present study was not designed to investigate the cause of sucrase insufficiency, which could be genetic [51, 52], acquired due to inflammation, cachexia, and anticancer therapy [53] or specifically related to the fructose component or the GLUT-5 transporter that might be involved [54]. …”