Research laboratory of
Esteban G. Burchard, MD, MPH

Study Populations & Recruitment Staff

Study populations

map of USA, Mexico, and the Caribbean showing names and locations of associated project researchers

The GALA and SAGE studies investigate the interactions of genetic and environmental risk factors that influence asthma and asthma-related traits among children and adolescents.

Our gene-environment study of asthma in minority children is the largest in the United States. We recruited more than 9,000 participants with detailed measures of asthma, pulmonary function testing, bronchodilator drug response, genome-wide SNP data, detailed measures of air pollution, exposure to tobacco smoke, socioeconomic status, discrimination, and acculturation. These study populations consist of four independent recruitment efforts:

  1. Genetics of Asthma in Latino Americans (GALA I study)
  2. Genes-environments & Admixture in Latino Americans (GALA II study)
  3. Study of African Americans, Asthma, Genes, & Environments (SAGE I)
  4. Study of African Americans, Asthma, Genes, & Environments (SAGE II)

GALA I is a family-based Latino study. SAGE I is a parallel case-control study in participants ages 8-40. Both GALA II and SAGE II are parallel case-control studies using similar protocols and questionnaires as described in Nishimura (AJRCCM 2013). Subjects were recruited from five urban study centers across the mainland U.S. and Puerto Rico. We have genome-wide SNP genotypes on all participants and air pollution and tobacco data on 5,138 subjects. Latino children were recruited from the San Francisco Bay Area, Chicago, Houston, New York City, and Puerto Rico. African American children were recruited from the SF Bay Area.

Participants were 8-21 years old at time of recruitment and had physician-diagnosed asthma. Healthy controls had no reported history of asthma or allergies, use of medication for allergies, or any symptoms of wheezing or shortness of breath during their lifetime. All subjects with asthma must have had asthma symptoms and/or asthma medication use within the last two years, with no history of other lung or chronic non-allergic illnesses; active smokers were excluded. Parents and grandparents must have self-identified as Latino (GALA I & II) or African American (SAGE I & II).

We have detailed clinical measures (bronchodilator response testing, spirometry, exhaled nitric oxide, skin pigmentation, skin prick testing, complete blood counts, and IgE measurements), biologic specimens (whole blood, RNA, DNA, and nasal epithelia), geocoded air pollution measures, and questionnaire-based information regarding social and environmental risk factors. Genome-wide SNP genotypes are available for all GALA II and SAGE participants from the Affymetrix 6.0 array or Axiom LAT1 array (Affymetrix, >800,000 SNPs) for GALA II and SAGE II.

Number of individuals enrolled in our studies

Study

Ethnicity

Total

Cases

Controls

Parents

GALA I

Hispanic/Latino

2499

707

378

1414

GALA II

Hispanic/Latino

4885

2233

2478

174

SAGE I

African Americans

494

308

186

NA

SAGE II

African Americans

1736

958

778

NA

Total

Hispanic/Latino or African Americans

9614

4206

3820

1588

Poor response to therapies contributes to racial/ethnic disparities in asthma morbidity and mortality. Therefore, one of the main goals of the lab is to study the response to albuterol, the most commonly prescribed asthma medication in the world and the mainstay of acute asthma management across all racial/ethnic groups. We have a large collection of DNA samples from 4,111 participants with asthma with measurements of bronchodilator response (BDR).

Total number of participants with asthma included in GALA and SAGE studies of bronchodilator response (BDR)

 

High responders

Low responders

African Americans

601

617

Mexicans

319

642

Puerto Ricans

725

631

Other Latinos

221

355

Total

1866

2245

High responders and low responders are defined as BDR ≥8% and BDR <8%, respectively. BDR ≥8% is well correlated with asthma and wheezing in children.

Recruitment staff

The Burchard Lab has a full-time clinical recruiter who is trained in performing spirometry, phlebotomy, and clinical characterization, and in administering clinical questionnaires. In addition, we have a clinical coordinator who organizes all clinical recruitment inside and outside UCSF. Together, the recruiter and coordinator ensure that recruitment and phenotype procedures are standardized across all sites. Both will travel to all our clinical sites and provide standardized training on phenotype characterization and questionnaire administration.