Lack of association of atopy/asthma and the interleukin-4 receptor alpha gene in Japanese.
BACKGROUND
Susceptibility to the development of atopic diseases is known to involve genetic factors. Several investigators have reported the interleukin-4 (IL-4) receptor alpha gene to be involved in the development of atopy. Recent study has shown that the R allele of a polymorphism in the IL-4 receptor alpha chain gene (Q576R) to be associated with atopy.


OBJECTIVE
The objective of this study was to evaluate the possible role of the IL-4 receptor alpha gene in modulating allergic response and asthma in the Japanese population.


METHODS
We conducted linkage analysis using microsatellite markers flanking the IL-4 alpha receptor gene in 82 families ascertained through asthmatic children. The IL-4 receptor Q576R polymorphism was also genotyped by PCR-restriction fragment length polymorphism analysis.


RESULTS
We did not find evidence for linkage of the asthma and atopy phenotypes with the markers D16S298 and D16S403 (P = 0.10 and P = 0.56, respectively, for the atopy phenotype and P = 0.17 and P = 0.60, respectively, for the asthma phenotype). The IL-4 receptor R576 allele was not preferentially transmitted to atopy- or asthma-affected children (chi2 = 1.67, P = 0.24 for atopy and chi2 = 0.91, P = 0.40 for asthma). In addition, the prevalence of the R576 allele among parents with and without atopy was similar, 20 of 81 (24.7%) parents with atopy and 22 of 77 (28.6%) parents without atopy.


CONCLUSIONS
Our findings indicate that the IL-4 receptor alpha gene does not exert a substantial influence on the inheritance of atopy or asthma in this Japanese population.
Noguchi
E
E
Department of Pediatrics, Institute of Clinical Medicine, Tsukuba, Japan.
Shibasaki
M
M
Arinami
T
T
Takeda
K
K
Yokouchi
Y
Y
Kobayashi
K
K
Imoto
N
N
Nakahara
S
S
Matsui
A
A
Hamaguchi
H
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics; D003233:Conjunctivitis, Allergic / Q000235:genetics*; D017931:DNA Primers / Q000737:chemistry; D003876:Dermatitis, Atopic / Q000235:genetics*; D008040:Genetic Linkage; D006801:Humans; D007223:Infant; D007564:Japan; D018895:Microsatellite Repeats; D008875:Middle Aged; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D019948:Receptors, Interleukin-4 / Q000235:genetics*; D012220:Rhinitis / Q000235:genetics*
D017931:DNA Primers; D019948:Receptors, Interleukin-4