title: Complex two-gene modulation of lung disease severity in children with cystic fibrosis.
abstract: Although cystic fibrosis (CF) is a monogenic disease, its clinical manifestations are influenced in a complex manner. Severity of lung disease, the main cause of mortality among CF patients, is likely modulated by several genes. The mannose-binding lectin 2 (MBL2) gene encodes an innate immune response protein and has been implicated as a pulmonary modifier in CF. However, reports have been conflicting, and interactions with other modifiers have not been investigated. We therefore evaluated the association of MBL2 with CF pulmonary phenotype in a cohort of 1,019 Canadian pediatric CF patients. MBL2 genotypes were combined into low-, intermediate-, and high-expression groups based on MBL2 levels in plasma. Analysis of age at first infection with Pseudomonas aeruginosa demonstrated that MBL2 deficiency was significantly associated with earlier onset of infection. This MBL2 effect was amplified in patients with high-producing genotypes of transforming growth factor beta 1 (TGFB1). Similarly, MBL2 deficiency was associated with more rapid decline of pulmonary function, most significantly in those carrying the high-producing TGFB1 genotype. These findings provide evidence of gene-gene interaction in the pathogenesis of CF lung disease, whereby high TGF-beta1 production enhances the modulatory effect of MBL2 on the age of first bacterial infection and the rate of decline of pulmonary function.
authors.affiliation: Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Ruslan
authors.initials: R
authors.lastname: Dorfman
authors.forename: Andrew
authors.initials: A
authors.lastname: Sandford
authors.forename: Chelsea
authors.initials: C
authors.lastname: Taylor
authors.forename: Baisong
authors.initials: B
authors.lastname: Huang
authors.forename: Daisy
authors.initials: D
authors.lastname: Frangolias
authors.forename: Yongqian
authors.initials: Y
authors.lastname: Wang
authors.forename: Richard
authors.initials: R
authors.lastname: Sang
authors.forename: Lilian
authors.initials: L
authors.lastname: Pereira
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.forename: Yves
authors.initials: Y
authors.lastname: Berthiaume
authors.forename: Lap-Chee
authors.initials: LC
authors.lastname: Tsui
authors.forename: Peter D
authors.initials: PD
authors.lastname: Paré
authors.forename: Peter
authors.initials: P
authors.lastname: Durie
authors.forename: Mary
authors.initials: M
authors.lastname: Corey
authors.forename: Julian
authors.initials: J
authors.lastname: Zielenski
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008168:Lung / Q000503:physiopathology; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood / Q000235:genetics*; D011552:Pseudomonas Infections / Q000209:etiology*; D011550:Pseudomonas aeruginosa; D012737:Sex Factors; D053773:Transforming Growth Factor beta1 / Q000235:genetics*
chemical_list: C445619:MBL2 protein, human; D037601:Mannose-Binding Lectin; D053773:Transforming Growth Factor beta1