Congenital Sucrase-Isomaltase Deficiency (CSID) Genetic Prevalence Study (GPS)

Study Overview
=================
Brief Summary
-----------------
Congenital sucrose-isomaltase deficiency (CSID) is a rare, genetic disease in which mutations in the sucrose-isomaltase (SI) gene cause digestion problems of sucrose resulting in diarrhea and abdominal pain. Children with chronic, idiopathic diarrhea or abdominal pain will have their sucrose-isomaltase gene assessed for a panel of known CSID mutations to determine the prevalence of these mutations in an enriched population and also determine functional deficiency using a breath test.

Official Title
-----------------
A Multi-Center Study of the Prevalence of Known Congenital Sucrase-Isomaltase Deficiency (CSID) Genetic Variants and Functional Sucrase Activity by 13C-Sucrose Breath Test in Children With Chronic Diarrhea or Chronic Abdominal Pain

Conditions
-----------------
Congenital Sucrase-isomaltase Deficiency (CSID)

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Must be 18 years of age or younger. A primary clinical diagnosis of chronic idiopathic diarrhea or chronic abdominal pain for at least 4 weeks. English or Spanish speaking subjects and parent(s)/guardian only. Parental consent from one parent/guardian and also subject assent when appropriate based on individual IRB requirements. Exclusion Criteria: Any condition(s) or finding(s) that in the opinion of the principal investigator suggests an alternative diagnosis for his/her gastrointestinal symptoms. Abdominal pain primarily related to constipation. Suspected gastrointestinal infectious disease. No current use of sacrosidase (Sucraid® Oral Solution). Known gastrointestinal disease such as celiac disease. Prior consumption of an investigational medication within the last 4 weeks. Antibiotics in the last 2 weeks, and no history of viral gastroenteritis within that same period of time. Known Hepatitis B or C infection (positive HBsAg or HCV within 6 months of enrollment) or Subject-Pugh Class C liver disease of any cause, HIV infection, tuberculosis, Clostridia difficile co-infection, cancer or systemic infections. Severe neurologic impairment that would prevent them from reporting a history of abdominal pain. Receiving or received biologic therapies (including infliximab, adalimumab, natalizumab) within 3 months prior to or at enrollment. Present or past use of immune modulators therapy (e.g., azathioprine, 6MP, methotrexate). Planned or previous abdominal surgery (e.g., bowel resection). Subjects with severe, uncontrolled systemic diseases. Presence of clinical alarm signs, including hypotension, anemia requiring blood transfusions, altered mental status, or inability to tolerate food and/or fluids by mouth.

Ages Eligible for Study
-----------------
Maximum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| CSID Mutations<br>Individual has one or more known CSID mutations. | |
| Control<br>Individual does not have any known CSID mutations. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence of CSID Genetic Variants | Prevalence of CSID genetic variants in subjects 18 years of age or younger with a primary symptom of chronic idiopathic diarrhea or chronic abdominal pain without constipation. | 1 year |