A Polymorphism in the Chitotriosidase Gene Associated with Risk of Mycetoma Due to Madurella mycetomatis Mycetoma–A Retrospective Study

Background: madurella mycetomatis is the most prevalent causative agent of eumycetoma in sudan,an infection characterized by the formation of grains. many patients are exposed to the causative agent,however only a small number develop infection. m. mycetomatis contains chitin in its cell wall,which can trigger the human immune system. polymorphisms in the genes encoding for the chitin-degrading enzymes chitotriosidase and amcase were described,resulting in altered chitinase activity. we investigated the association between 4 of these polymorphisms and the incidence of m. mycetomatis mycetoma in a sudanese population. methodology: polymorphisms studied in 112 eumycetoma patients and 103 matched controls included a 24-bp insertion in the chitotriosidase gene (rs3831317),resulting in impaired chitinase activity and single nucleotide polymorphism (snp) in the amcase gene (rs61756687),resulting in decreased amcase activity. also,a snp (rs41282492) and a 10-bp insertion in the 5’utr region of the amcase gene (rs143789088) were studied,both resulting in increased amcase activity. dna was isolated from blood and genotypes were determined using pcr-rflp. principal findings: histological staining proved the presence of chitin in the fungal grain. the polymorphism resulting in decreased chitotriosidase activity was associated with increased odds of eumycetoma (odds ratio 2.9; p = 0.004). no association was found for the polymorphisms in the genes for amcase (all p>0.05). conclusion: decreased chitotriosidase activity was associated with increased risk of m. mycetomatis mycetoma. © 2015 verwer et al.