Background and Aims: Cycloxygenase-2 (COX-2) catalyses the rate limiting step of prostaglandin biosynthesis. Despite previous studies, it is still unclear whether COX-2 is beneficial or detrimental to cardiovascular risk. The aim of this study was to examine the -765G>C (rs20417) PTGS2 promoter gene variant, which encodes COX-2, in relation to markers of cardiovascular risk in a sample of well-characterised subjects with diabetes mellitus.

The proband was of Arabic descent and evaluated for intractable diarrhea and poor growth. Molecular testing identified a nonsense mutation in the sucrase-isomaltase (SI) gene consistent with a diagnosis of sucrase-isomaltase deficiency (CSID). Appropriate treatment led to resolution of symptoms and improved growth. This case represents the first report of CSID with molecular confirmation in a patient without known European ancestry and demonstrates the importance of genetic testing for congenital diarrheal disorders.