Asthma and atopy linked to chromosome 5 Scientists have found significant evidence for linkage of atopy to markers in chromosome 5q31-33, suggesting variants in these genes may increase an individual's susceptibility to asthma. Chromosome 5q31-33 has long been a focus of interest for assessing linkage of asthma- and atopy-related traits because of the large number of genes in the region that regulate functions known to be associated with atopy. A research team from the scaring of lungs by asthma scaring of lungs by asthma University of Arizona Health Sciences Center in Tucson, US, sought to clarify and quantify phenotypes that might be characterised by related asthma and atopy traits. The investigation involved 468 Hispanic and non-Hispanic white children who had been enrolled in a respiratory study and had complete information on 24 items. These items included skin test response to seven allergens, total serum immunoglobulin E levels, history of presence or absence of wheezing, asthma attacks, hay fever and cough. The researchers applied asthma problems scaring of lungs by asthma the statistical techniques of principal components and factor analysis to the items. Resulting factor-score coefficients were then applied to the 468 children and their 409 siblings, and quantitative factor scores were derived for a total of 877 children. Single-point and multi-point nonparametric sib-pair analyses were performed to assess linkage to markers on chromosome 5q31-33. For comparison, analyses were also performed for individual items. Significant evidence was found for linkage of composite atopy-related phenotype with markers in chromosome 5q31-33. However, the baby asthma canada scaring of lungs by asthma asthma phenotype, derived as a second factor after removing the variance associated with the atopy factor, showed no evidence for linkage with these markers. The researchers said these results suggested that variants in genes in chromosome 5q might determine atopy, and through this mechanism, increase susceptibility to asthma. "Thus, although asthma is an atopic disease, the exact nature of the link between asthma and atopy remains to be determined," wrote the study authors in the Journal of Allergy and asthma buteyko scaring of lungs by asthma Clinical Immunology.
