Genetic Association With Various Severities, Phenotypes and Endotypes of Asthma.

Currently, many studies on asthma genetics are limited by the dominance of populations of European descent. In addition, there are few genetic studies that focus on moderate-to-severe asthma. There is limited information on genetics associated with asthma in Chinese. An earlier meta-analysis found that ADAM33, FcεRIb, RANTES, TNF-a, ACE, b2-AR, IL-4R and IL-13 genes could be proposed as asthma susceptible genes in the Chinese population. However, given the limited number of studies, more data are required to validate these associations. Future research must address key issues such as the broad clinical variability of asthma and the underrepresentation of populations of non-European heritage. Endotype-specific SNPs and unique biological insights may be obtained by conducting GWAS/EWAS on homogeneous populations of more therapy-resistant T2-low, adult-onset, obesity-associated asthma or asthma with particular co-morbidities. Objectives Primary objective To investigate the association between genetic polymorphisms and various severities of asthma (e.g. mild, moderate, severe). Secondary objectives 1. Identify the most common genetic variants associated with asthma in Chinese patients. 2. Determine the frequency and distribution of these genetic variants in Chinese patients compared to healthy controls. 3. Explore the potential interactions between genetic and environmental factors in the development of asthma in Chinese patients. 4. Explore the frequency and distribution of these genetic variants in patients with various phenotypes and endotypes (examples: including TH2 high asthma, Asthma COPD overlap, poor lung function, onset of illness) This is a prospective observational study in outpatients with asthma seen and treated by physicians in the Prince of Wales Hospital. A total of 1000 asthma patients will be enrolled, along with 1000 controls matched for age, sex, and ethnicity. All participants will provide blood samples for genetic analysis, and clinical data will be collected from medical records and patient interviews. Genetic variants will be genotyped using high-throughput sequencing methods.