title: Association of 24 bp duplication of human CHIT1 gene with asthma in a heterozygous population of north India: a case-control study.
abstract: OBJECTIVE
  CHIT1 is expressed by pulmonary macrophages, which is typically the site of entry for many environmental fungi that may increase the risk of pulmonary fungal infection and lead to hypersensitivity. The conserved expression of this gene in humans suggests its physiological importance in the mammalian lung.
  
  
  METHODS
  The present study was conducted with a total of 964 subjects, including 483 healthy controls and 481 asthma patients. DNA samples were extracted from blood, and the genotyping was done using polymerase chain reaction method.
  
  
  RESULTS
  Statistical analysis revealed that the 24 bp duplication in CHIT1 gene polymorphism shows highly significant association in heterozygous (wild/dup) genotype with OR 1.74, 95 % CI (1.29-2.36), and p = 0.000. However, the homozygous mutant genotype (dup/dup) was found to be non-significant with OR 1.06, 95% CI (0.69-1.63), and p = 0.786. The combination of both wild/dup and dup/dup was also found to be highly significant with OR 1.57, 95% CI (1.18-2.11), and p = 0.002.
  
  
  CONCLUSIONS
  This is the first study conducted in India which reports a significant association between 24 bp duplication in CHIT1 gene polymorphism and asthma in the studied North Indian population.
authors.affiliation: Department of Biotechnology, Panjab University, Chandigarh, India.
authors.forename: Shweta
authors.initials: S
authors.lastname: Sinha
authors.forename: Jagtar
authors.initials: J
authors.lastname: Singh
authors.forename: Surinder Kumar
authors.initials: SK
authors.lastname: Jindal
authors.forename: Niti
authors.initials: N
authors.lastname: Birbian
authors.forename: Neha
authors.initials: N
authors.lastname: Singla
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics*; D020029:Base Pairing; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D020440:Gene Duplication; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006579:Heterozygote; D006596:Hexosaminidases / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010641:Phenotype; D011110:Polymorphism, Genetic; D012307:Risk Factors; D055815:Young Adult
chemical_list: D006596:Hexosaminidases; C086400:chitotriosidase