Ruth Kohen

Irritable bowel syndrome is a frequent gastrointestinal disorder of unknown etiology. The serotonin transporter regulates the intensity and duration of serotonin signaling in the gut and is, therefore, an attractive candidate gene for irritable bowel syndrome. Previous studies investigating the 5-HTTLPR and Stin2 VNTR polymorphisms of the serotonin transporter have proved inconclusive. In this exploratory study we therefore expanded the search for a possible association of the serotonin transporter with irritable bowel syndrome to include not only the 5-HTTLPR and Stin2 VNTR length polymorphisms, but also the functional single nucleotide polymorphism rs25531. We genotyped 186 patients with irritable bowel syndrome and 50 healthy control subjects raging in age from 18 to 70 years. Carriers of the rare G allele of rs25531 had approximately threefold increased odds of irritable bowel syndrome compared with healthy controls (OR 3.3, 95% CI 1.1–9.6). Our findings suggest that further investigation of the possible role of the serotonin transporter in the etiology of IBS is warranted.

Approximately 33% of patients experience major depression after stroke.¹ The etiology of poststroke depression (PSD) is thought to be multifactorial, involving psychosocial and biological mechanisms.² A premorbid history of depression and high levels of disability increase the risk of depression in stroke survivors, yet these factors are poor predictors of who will become depressed after stroke and who will not.³