Sex- and age-of-onset-based locus heterogeneity in asthma

Area of Science:

• Genetics
• Pulmonology
• Bioinformatics

Background:

• Asthma is a complex respiratory condition with a significant genetic basis.
• Genome-wide linkage studies suggest locus heterogeneity is a key aspect of asthma genetics.
• Identifying specific genetic loci is crucial for understanding asthma pathogenesis.

Purpose of the Study:

• To reduce locus heterogeneity in asthma genetic studies.
• To investigate sex, parental allele origin, and age of onset as bases for stratification.
• To identify novel asthma susceptibility loci and explain heterogeneity at known loci.

Main Methods:

• Analysis of genotype and phenotype data from genome-wide linkage searches across three populations.
• Stratification of data based on sex of affected individuals.
• Stratification based on parental origin of shared alleles in affected sib pairs.
• Stratification based on age of onset of wheeze.

Main Results:

• Evidence for linkage to specific chromosomal regions in individuals of a particular sex.
• Excess maternal allele sharing identified on chromosomes 9 and 11.
• Linkage to chromosomes 2 and 6 associated with late and early onset of wheeze, respectively.
• Stratification variables appear appropriate for certain asthma susceptibility loci.

Conclusions:

• The chosen stratification factors (sex, parental origin, age of onset) are effective for analyzing asthma susceptibility loci.
• This approach can aid in the fine mapping of asthma genetic loci.
• Differences in these stratification variables may explain inconsistencies in previous linkage study findings.