Polymorphisms in the mannan-binding lectin gene are not associated with questionnaire-reported respiratory tract infections in children.
BACKGROUND
Low mannan-binding lectin (MBL) levels, caused by MBL2 polymorphisms, are suggested to contribute to susceptibility to respiratory tract infections (RTIs), particularly early in life. Large-scale replication of previous associations is needed, however. We investigated the association between MBL2 polymorphisms and the frequency of RTI in a large population-based birth cohort of white children.


METHODS
The frequency of RTI was prospectively assessed by annual parental questionnaires until children were 4 years of age. Thirteen polymorphisms in MBL2 were determined in 987 Dutch children. Haplotypes, previously shown to be associated with functional levels of MBL, were constructed, and their associations with the frequency of RTI during year 1, year 2, and the first 4 years of life were assessed. High-producing, intermediate-producing, and deficient MBL2 genotypes were defined on the basis of exon 1 and Y/X promoter polymorphisms.


RESULTS
No differences were found between investigated polymorphisms and haplotype frequencies in the population as a whole or between the groups with frequent, moderately frequent, or no RTIs reported. Deficient MBL2 genotypes were not associated with an increased risk of RTI (odds ratio, 0.71 [95% confidence interval, 0.25 to 2.05]) during years 1-4 of life. This was also true when year 1 and year 2 were studied separately.


CONCLUSIONS
These results suggest that, at the population level, MBL2 polymorphisms do not contribute to the risk of questionnaire-reported RTI in white children.
Department of Pediatrics, Wilhelmina Children's Hospital, University Medical Center Utrecht, University of Utrecht, Lundlaan 6, Utrecht, The Netherlands. j.ruskamp@umcutrecht.nl
Jopje M
JM
Ruskamp
Maarten O
MO
Hoekstra
Dirkje S
DS
Postma
Marjan
M
Kerkhof
Renske W
RW
Bottema
Gerard H
GH
Koppelman
Maroeska M
MM
Rovers
Alet H
AH
Wijga
Johan C
JC
de Jongste
Bert
B
Brunekreef
Elisabeth A
EA
Sanders
D002648:Child; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D037601:Mannose-Binding Lectin / Q000235:genetics*; D011110:Polymorphism, Genetic; D012141:Respiratory Tract Infections / Q000235:genetics*; D011795:Surveys and Questionnaires
D037601:Mannose-Binding Lectin