[A preliminary study on the genetic susceptibility of asthma in a Chinese population]

To study the asthma genetic susceptibility by way of ccandidate region so as to accumulate data on the related loci in Chinese population and determine whether genetic susceptibility to asthma is linked to the chromosome region.

One hundred ninety-two samples from 32 families were collected from Zhaoan county in Fujian province. Two Rsa I polymorphic sites within uncoded region of the high-affinity IgE receptor beta chain gene (Fc(epsilon) RI-beta) located on chromosome 11q13 were detected by PCR/Rsa I restriction endonuclease digestion. The polymorphic markers D5S436 and D5S393 within chromosome 5q31-33 were amplified by PCR incorporated with radioactive isotope. The asthma family samples were compared with unrelated samples randomly selected from general population.

Genotypes containing A allele within intron 2 polymorphic site of Fc(epsilon) RI-beta gene were associated with asthma (P<0.05,OR = 2.039). Significant difference in the level of total serum IgE was noted among three genotypes of intron 2 polymorphic site of Fc(epsilon) RI-beta gene (P<0.05). The association between A allele and elevated total serum IgE was also significant (P<0.05, RR = 1.361). No relationship between exon 7 polymorphic site of Fc epsilonRI-beta gene and asthma was shown. By sib-pair analysis, significant evidence for linkage to asthma was observed with D5S436 (P<0.05) but not with D5S393. No significant linkage to total serum IgE was identified with both of these markers.

The above-accumulated data suggested that both Fc epsilonRI-beta gene and chromosome 5q31-33 could be very attractive candidate gene and region for further studies in Chinese population, and to confirm these preliminary results, more markers within these regions merit testing in additional population samples.