We observed inconsistent conclusions regarding the genetic role of glutathione S-transferase gene polymorphisms, including glutathione S-transferase M1 (<i>GSTM1</i>), glutathione S-transferase T1 (<i>GSTT1</i>) present/null, and glutathione S-transferase pi <i>(GSTP1</i>) Ile105Val polymorphisms, in the susceptibility to nasal or colorectal polyposis (NP or CP).
The GSTM1 and GSTT1 deletion polymorphisms, and the single nucleotide polymorphisms in GSTP1 (A313G) and in GSTA1 (C-69T) were assessed among 746 cases who developed colorectal adenomas and 698 endoscopy-based controls without any type of colorectal polyps.