title: High prevalence of chitotriosidase deficiency in Peruvian Amerindians exposed to chitin-bearing food and enteroparasites.
abstract: The human genome encodes a gene for an enzymatically active chitinase (CHIT1) located in a single copy on Chromosome 1, which is highly expressed by activated macrophages and in other cells of the innate immune response. Several dysfunctional mutations are known in CHIT1, including a 24-bp duplication in Exon 10 causing catalytic deficiency. This duplication is a common variant conserved in many human populations, except in West and South Africans. Thus it has been proposed that human migration out of Africa and the consequent reduction of exposure to chitin from environmental factors may have enabled the conservation of dysfunctional mutations in human chitinases. Our data obtained from 85 indigenous Amerindians from Peru, representative of populations characterized by high prevalence of chitin-bearing enteroparasites and intense entomophagy, reveal a very high frequency of the 24-bp duplication (47.06%), and of other single nucleotide polymorphisms which are known to partially affect enzymatic activity (G102S: 42.7% and A442G/V: 25.5%). Our finding is in line with a founder effect, but appears to confute our previous hypothesis of a protective role against parasite infection and sustains the discussion on the redundancy of chitinolytic function.
authors.affiliation: Department of Biology, Università degli Studi di Padova, Padova, Italy; Facultad de Ciencias Biologicas, Universidad Nacional de Trujillo, Trujillo, Peru.
authors.forename: N
authors.initials: N
authors.lastname: Manno
authors.affiliation: Division of Molecular and Cellular Science, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Sherratt
authors.affiliation: Department of Biology, Università degli Studi di Padova, Padova, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Boaretto
authors.affiliation: Facultad de Ciencias Biologicas, Universidad Nacional de Trujillo, Trujillo, Peru.
authors.forename: F Mejìa
authors.initials: FM
authors.lastname: Coico
authors.affiliation: Facultad de Ciencias Sociales, Universidad Nacional de Trujillo, Trujillo, Peru.
authors.forename: C Espinoza
authors.initials: CE
authors.lastname: Camus
authors.affiliation: Facultad de Ciencias Biologicas, Universidad Nacional de Trujillo, Trujillo, Peru.
authors.forename: C Jara
authors.initials: CJ
authors.lastname: Campos
authors.affiliation: Dpt. of Chemical Sciences, Università di Catania and Institute of Biomolecular Chemistry, CNR, Catania, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Musumeci
authors.affiliation: Department DAFNAE, Università degli Studi di Padova, Legnaro, Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Battisti
authors.affiliation: School of Biology, University of Leeds, Leeds, United Kingdom.
authors.forename: R J
authors.initials: RJ
authors.lastname: Quinnell
authors.affiliation: Facultad de Ciencias Biologicas, Universidad Nacional de Trujillo, Trujillo, Peru.
authors.forename: J Mostacero
authors.initials: JM
authors.lastname: León
authors.affiliation: Department of Biology, Università degli Studi di Padova, Padova, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Vazza
authors.affiliation: Department of Biology, Università degli Studi di Padova, Padova, Italy.
authors.forename: M L
authors.initials: ML
authors.lastname: Mostacciuolo
authors.affiliation: Department of Biology, Università degli Studi di Padova, Padova, Italy. Electronic address: paoletti@bio.unipd.it.
authors.forename: M G
authors.initials: MG
authors.lastname: Paoletti
authors.affiliation: Division of Molecular and Cellular Science, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom.
authors.forename: F H
authors.initials: FH
authors.lastname: Falcone
mesh_terms: D000818:Animals; D002686:Chitin / Q000737:chemistry* / Q000235:genetics; D004032:Diet; D006596:Hexosaminidases / Q000172:deficiency / Q000235:genetics*; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D007199:Indians, South American; D008264:Macrophages / Q000378:metabolism / Q000469:parasitology; D009154:Mutation; D010271:Parasites / Q000737:chemistry / Q000378:metabolism; D010568:Peru; D020641:Polymorphism, Single Nucleotide
chemical_list: D002686:Chitin; D006596:Hexosaminidases; C086400:chitotriosidase
keywords: 24-bp duplication/H-allele; Amazonian Amerindians; Chitin-bearing parasites; Exposure to chitin; Human chitotriosidase; Single nucleotide polymorphisms