Evaluation of 24 Bp Duplication of Chitotriosidase Gene in Pulmonary Tuberculosis in Zahedan, Southeast Iran: A Preliminary Report

Chitotriosidase (CHIT1), the major chitinase in human airways, is expressed by pulmonary macrophage. Variation in the coding region with 24 bp duplication allele results in reduced CHIT1 activity.. The present study was designed to assess the impact of 24 bp duplication in exon 10 of human CHIT1 gene on pulmonary tuberculosis (PTB) risk..Patients and This case-control study was performed on 173 PTB patients and 164 healthy subjects in Zahedan, southeast Iran. Polymerase chain reaction (PCR) was used to detect the variant.. Homozygous wild type, heterozygous and homozygous mutant frequencies of CHIT1 24 bp duplication polymorphism were 43.9%, 43.9% and 12.2% in controls and 42.8%, 45.1% and 12.1% in PTB patients. We found the mutant allele frequency of 34.2% and 34.7% in controls and cases, respectively. Chi-square comparison of PTB and control subjects and logistic regression analysis revealed no association between CHIT1 24 bp duplication and PTB.. In conclusion, CHIT1 24 bp duplication might not be a candidate gene for susceptibility to PTB. Larger studies are necessary to confirm these findings in various populations..