Association of polymorphisms in the mast cell chymase gene promoter region (-1903 g/A) and (TG)n(GA)m repeat downstream of the gene with bronchial asthma in children.
BACKGROUND
Mast cell chymase is a mediator of inflammation and remodeling in the asthmatic lung. Although various studies have examined the association between the -1903 G/A single nucleotide polymorphism (SNP)in the mast cell chymase gene (CMA1) and allergic phenotypes, the results have been inconsistent. A (TG)n(GA)m repeat polymorphism 254 base pairs downstream of CMA1 has been reported in adult asthmatics. We investigated the relationship between these CMA1 genetic variants and childhood asthma in Egyptian children.


METHODS
A case-control study was undertaken in 15 children (6-10 years old) with bronchial asthma enrolled consecutively during exacerbation and 15 age-matched and sex-matched nonasthmatic control subjects. Genotyping was performed by polymerase chain reaction (PCR) restriction fragment length polymorphism to search for polymorphisms in the CMA1 gene promoter region (-1903 G/A) and PCR amplification followed by sequencing to detect the (TG)n(GA)m repeat 254 base pairs downstream of the gene.


RESULTS
Our data showed a positive association between the CMA1 -1903 G/A SNP and asthma in children. The G allele was detected in 70% of patients while the A allele was more frequent in the controls (83.3%). Concerning the (TG)n(GA)m repeat, allele 39 was only present in asthmatics while allele 37 was more common in controls.


CONCLUSIONS
We report the association of the -1903 G/A CMA1 SNP and (TG)n(GA)m repeat polymorphism with bronchial asthma in a group of Egyptian children. These polymorphisms are possible determinants of asthma susceptibility and may be involved in regulating immunoglobulin E levels.
Hossny
E M
EM
Department of Pediatrics, Ain Shams University, Cairo, Egypt. elham.hossny@gmail.com
Amr
N H
NH
Elsayed
S B
SB
Nasr
R A
RA
Ibraheim
E M
EM
D001249:Asthma / Q000235:genetics* / Q000276:immunology; D016022:Case-Control Studies; D015550:Cell Degranulation / Q000276:immunology; D002648:Child; D053818:Chymases / Q000235:genetics* / Q000276:immunology; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008407:Mast Cells / Q000276:immunology / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics* / Q000276:immunology; D020080:Tandem Repeat Sequences / Q000276:immunology
D007073:Immunoglobulin E; D053818:Chymases