title: The chitinase and chitinase-like proteins: a review of genetic and functional studies in asthma and immune-mediated diseases.
abstract: OBJECTIVE
  The present review provides an overview of the chitinase and chitinase-like proteins, chitotriosidase (CHIT1), YKL-40, and acid mammalian chitinase, and summarizes the genetic studies of asthma and immune-mediated diseases with polymorphisms in the genes encoding these proteins, CHIT1, CHI3L1, and CHIA, respectively.
  
  
  RESULTS
  Polymorphisms in the CHIT1, CHIA, and CHI3L1 genes influence chitotriosidase enzyme activity, acid mammalian chitinase activity, and YKL-40 levels, respectively. Regulatory SNPs in CHI3L1 were also associated with asthma, atopy, and immune-mediated diseases, and nonsynonymous SNPs in CHIA were associated with asthma. No CHIT1 polymorphisms, including a common nonfunctional 24-bp duplication allele, have been associated with asthma.
  
  
  CONCLUSIONS
  These genes represent novel asthma susceptibility genes. Variations in CHI3L1 and CHIA have been associated with asthma risk. Polymorphisms in CHIT1 have not yet been associated with asthma, but few studies have been reported. Given that chitotriosidase is the major chitinase in the airways and a common nonfunctional allele is present in many populations, additional studies of this gene are warranted. Lastly, studies of all three genes need to be conducted in populations of diverse ancestries.
authors: Department of Human Genetics, The University of Chicago, Illinois 60636, USA. c-ober@genetics.uchicago.edu
authors: Carole
authors: C
authors: Ober
authors: Geoffrey L
authors: GL
authors: Chupp
mesh_terms: D054392:Adipokines; D001249:Asthma / Q000201:enzymology* / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology*; D000071451:Chitinase-3-Like Protein 1; D002688:Chitinases / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D020022:Genetic Predisposition to Disease; D005828:Genetics, Population; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006596:Hexosaminidases / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D037102:Lectins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011110:Polymorphism, Genetic
chemical_list: D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins; D006596:Hexosaminidases; C086400:chitotriosidase; C499254:CHIA protein, human; D002688:Chitinases