Genome-wide association study of leukotriene modifier response in asthma

Area of Science:

• Pharmacogenomics
• Asthma treatment
• Genetic association studies

Background:

• Patient responses to leukotriene modifiers (LTMs) vary significantly.
• Previous candidate gene studies suggested genetic factors, but no genome-wide association study (GWAS) had been reported.
• Understanding genetic influences can optimize LTM therapy.

Purpose of the Study:

• To conduct the first GWAS of LTM response.
• To identify genetic loci associated with therapeutic response to zileuton and montelukast.
• To investigate gene-environment interactions in LTM treatment efficacy.

Main Methods:

• Utilized DNA and phenotypic data from two placebo-controlled trials of zileuton response (N=526).
• Employed a gene-environment (G × E) GWAS model to assess 12-week change in forced expiratory volume in 1 second (ΔFEV1).
• Replicated top single-nucleotide polymorphism (SNP) associations in independent zileuton and montelukast cohorts.

Main Results:

• rs12436663 in MRPP3 achieved genome-wide significance (P=6.28 × 10(-08)) for zileuton response.
• Homozygous carriers of rs12436663 exhibited reduced mean ΔFEV1 with zileuton.
• rs517020 in GLT1D1 was associated with poorer response to both montelukast and zileuton (combined P=1.25 × 10(-07)).

Conclusions:

• Identified novel genetic loci, MRPP3 and GLT1D1, influencing LTM therapeutic response.
• These findings provide new insights into the genetic basis of variable LTM efficacy.
• Highlights the potential for pharmacogenetics to personalize asthma treatment strategies.