Complex two-gene modulation of lung disease severity in children with cystic fibrosis.
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.
Dorfman
Ruslan
R
Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada.
Sandford
Andrew
A
Taylor
Chelsea
C
Huang
Baisong
B
Frangolias
Daisy
D
Wang
Yongqian
Y
Sang
Richard
R
Pereira
Lilian
L
Sun
Lei
L
Berthiaume
Yves
Y
Tsui
Lap-Chee
LC
Paré
Peter D
PD
Durie
Peter
P
Corey
Mary
M
Zielenski
Julian
J
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*
C445619:MBL2 protein, human; D037601:Mannose-Binding Lectin; D053773:Transforming Growth Factor beta1