Chitotriosidase, a prematurely orphan enzyme
- 9 Downloads
Human Chitotriosidase (CHIT) is a member of the chitinase family and is synthesized by activated macrophages. Recently, a genetic polymorphism was found to be responsible for the common deficiency in CHIT activity, frequently encountered in different population. We analyzed the CHIT gene in some ethnic groups from Mediterranean and frican area, to evaluate whether the CHIT gene polymorphism correlates with the changes in environmental features and the disappearance of parasitic diseases. We evaluate the plasma CHIT activity and analyzed, by PCR, the Chit gene polymorphism in 100 Sicilian, 107 Sardinian and 99 Sub-Saharan subjects. We found an heterozygote frequency for a duplication of 24 base pair in exon 10 of 44,54% in Sicily and 32,71 % in Sardinia, whereas homozygous chit deficient were 5,45 % and 3,73%, respectively. On the contrary in Burkina Faso, a mesoendemic regio nforPlasmodium falciparum malaria and other intestinal parasites, a low incidence of CHIT mutation was found (heterozygous 2%) and any subject was homozygous for CHIT deficiency. Our results suggest that in sub-Saharan population the intact CHIT gene seems essential for sustaining resistance against chitin-coated parasitic disease, whereas the presence of CHIT gene polymorphism in Mediterranean population could be the result of a recent positive selection due to improved environmental conditions, which makes prematurely orphan this enzyme.
KeywordsChitotriosidase Polymorphism Sub-Saharan area Mediterranean area
Unable to display preview. Download preview PDF.
- Canudas J., Cenarro A., Civeira F., Garcia-Otin A.L., Aristegui R., Diaz C., Masramon X., Sol J.M., Hernandez G., Pocovi M. 2001. Chitotriosidase genotype and serum activity in subjects with combined hyperlipidemia: effect of the lipid-lowering agents, Atorvastatin and Bezafibrate. Metabolism 50: 447–450.CrossRefGoogle Scholar
- Araujo AC, Souto-Padron T, de Souza W. 1993. Cytochemical localization of carbohydrate residues in microfilariae of Wuchereria bancrofti and Brugia malayi. J Histochem Cytochem. 41: 571–8.Google Scholar
- Rosatelli MC, Dozy A, Faa V, Meloni A, Sardu R, Saba L, Kan YW, Cao A. 1992. Molecular characterization of beta-thalassemia in the Sardinian population. Am J Hum Genet. 50: 422–426.Google Scholar
- Cappellini MD, Martinez di Montemuros F, De Bellis G, Debernardi S, Dotti C, Fiorelli G. 1996. Multiple G6PD mutations are associated with a clinical and biochemical phenotype similar to that of G6PD Mediterranean. Blood 87: 3953–3958.Google Scholar