Whole-Genome sequencing of pharmacogenetic drug response in racially diverse children with asthma

Rationale: Albuterol, a bronchodilator medication, is the first-line therapy for asthma worldwide. There are significant racial/ethnic differences in albuterol drug response. Objectives: To identify genetic variants important for bronchodilator drug response (BDR) in racially diverse children. Methods: We performed the first whole-genome sequencing pharmacogenetics study from 1,441 children with asthma from the tails of the BDR distribution to identify genetic association with BDR. Measurements and Main Results: We identified populationspecific and shared genetic variants associated with BDR, including genome-wide significant (P,3.5331027) and suggestive (P, 7.0631026) loci near genes previously associated with lung capacity (DNAH5), immunity (NFKB1 and PLCB1), and b-Adrenergic signaling (ADAMTS3 and COX18). Functional analyses of the BDR-Associated SNP in NFKB1 revealed potential regulatory function in bronchial smooth muscle cells. The SNP is also an expression quantitative trait locus for a neighboring gene, SLC39A8. The lack of other asthma study populations with BDR and wholegenome sequencing data on minority children makes it impossible to perform replication of our rare variant associations. Minority underrepresentation also poses significant challenges to identify age-matched and population-matched cohorts of sufficient sample size for replication of our common variant findings. Conclusions: The lack of minority data, despite a collaboration of eight universities and 13 individual laboratories, highlights the urgent need for a dedicated national effort to prioritize diversity in research. Our study expands the understanding of pharmacogenetic analyses in racially/ethnically diverse populations and advances the foundation for precision medicine in at-risk and understudied minority populations.