Case Control Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pathophysiol. Jul 22, 2022; 13(4): 114-123
Published online Jul 22, 2022. doi: 10.4291/wjgp.v13.i4.114
Common polymorphisms of protein tyrosine phosphate non-receptor type 2 gene are not associated with risk of Crohn’s disease in Indian
Kaushik Chatterjee, Amit Kumar Dutta, Ashish Goel, Rekha Aaron, Vijayalekshmi Balakrishnan, Ajith Thomas, Anoop John, Rajeeb Jaleel, Deepu David, Reuben Thomas Kurien, SD Chowdhury, Ebby George Simon, AJ Joseph, Prasanna Premkumar, Anna B Pulimood
Kaushik Chatterjee, Amit Kumar Dutta, Ashish Goel, Rekha Aaron, Vijayalekshmi Balakrishnan, Ajith Thomas, Anoop John, Rajeeb Jaleel, SD Chowdhury, Anna B Pulimood, Department of Gastrointestinal Sciences, Christian Medical College and Hospital, Vellore 632004, Tamil Nadu, India
Deepu David, Reuben Thomas Kurien, Ebby George Simon, AJ Joseph, Department of Gastroenterology, Christian Medical College, Vellore 632004, Tamil Nadu, India
Prasanna Premkumar, Departments of Biostatistics, Christian Medical College, Vellore 632004, Tamil Nadu, India
Author contributions: Chatterjee K recruited the patients, collected the samples, and critically revised the manuscript; Dutta AK designed the study, analyzed the data, and wrote the manuscript; Balakrishnan V and Aaron R carried out laboratory analysis and critically revised the manuscript ; Samuel P helped with study design, data analysis, and critical revision; Goel A, Thomas A, John A, Jaleel R, David D, Kurien RT, Chowdhury SD, Simon EG, Joseph AJ, and Pulimood AB helped with data collection and critical revision of the manuscript; all authors have read and approved the final manuscript.
Supported by the CMC Vellore FLUID grant, No. 10360.
Institutional review board statement: The study was approved by the local institute review board and ethics committee (IRB Minute Number 10360, dated 3/11/2016).
Informed consent statement: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest statement: None of the authors have any conflict of interest to declare.
Data sharing statement: All the data have been presented in the manuscript. There are no additional data.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Amit Kumar Dutta, MD, Professor, Department of Gastrointestinal Sciences, Christian Medical College and Hospital, Ground Floor, Williams Building, Vellore 632004, Tamil Nadu, India. akdutta1995@yahoo.co.in
Received: January 17, 2022
Peer-review started: January 17, 2022
First decision: March 9, 2022
Revised: March 18, 2022
Accepted: May 22, 2022
Article in press: May 22, 2022
Published online: July 22, 2022
Abstract
BACKGROUND

Multiple genetic risk factors for Crohn’s disease (CD) have been identified. However, these observations are not consistent across different populations. The protein tyrosine phosphate non-receptor type 2 (PTPN2) gene plays a role in various aspects of host defense including epithelial barrier function, autophagy, and innate and adaptive immune response. Two common polymorphisms in the PTPN2 gene (rs2542151 and rs7234029) have been associated with risk of CD in Western countries.

AIM

To evaluate the association of PTPN2 gene polymorphisms with risk of CD in Indian population.

METHODS

We conducted a prospective case-control study. Patients with CD were recruited, and their clinical and investigation details were noted. Controls were patients without organic gastrointestinal disease or other comorbid illnesses. Two common polymorphisms in the PTPN2 gene (rs2542151 and rs7234029) were assessed. DNA was extracted from peripheral blood samples of cases and controls and target DNA was amplified using specific sets of primers. The amplified fragments were digested with restriction enzymes and the presence of polymorphism was detected by restriction fragment length polymorphism. The frequency of alleles was determined. The frequencies of genotypes and alleles were compared between cases and controls to look for significant differences.

RESULTS

A total of 108 patients with CD (mean age 37.5 ± 12.7 years, females 42.6%) and 100 controls (mean age 39.9 ± 13.5 years, females 37%) were recruited. For the single nucleotide polymorphism (SNP) rs7234029, the overall frequency of G variant genotype (AG or GG) was noted to be significantly lower in the cases compared to controls (35.2% vs 50%, P = 0.05). For the SNP rs2542151, the overall frequency of G variant genotype (GT or GG) was noted to be similar in cases compared to controls (43.6% vs 47%, P = 0.73). There were no significant differences in minor allele (G) frequency for both polymorphisms between the cases and controls. Both the SNPs had no significant association with age of onset of illness, gender, disease location, disease behaviour, perianal disease, or extraintestinal manifestations of CD.

CONCLUSION

Unlike observation form the West, polymorphisms in the PTPN2 gene (rs7234029 and rs2542151) are not associated with an increased risk of developing CD in Indian patients.

Keywords: PTPN2 gene, Crohn’s disease, Genetic polymorphism, Case-control study, Asia, Risk factor

Core Tip: Several genetic risk factors have been associated with Crohn’s disease and they have provided valuable insights into the pathogenesis of the disease. However, some of the genetic changes are not observed uniformly across all populations and hence it is essential to determine their occurrence in different populations. In this prospective case-control study, we investigated the association of two common polymorphisms in the protein tyrosine phosphate non-receptor type 2 (PTPN2) gene (rs7234029 and rs2542151) with risk of Crohn’s Disease in an Asian country. Our results showed that contrary to observation form the West, polymorphisms in the PTPN2 gene were not associated with an increased risk of developing Crohn’s disease.