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A Study of Immunogenetic Associations with Peanut Allergy Utilizing a Novel DNA Repository
Saturday, March 5, 2016
South Exhibit Hall H (Convention Center)
Jonathan A. Hemler, MD, Elizabeth S. Marston, MD, Jason H. Karnes, PhD, Andrew M. Glazer, PhD, Elizabeth J. Phillips, MD, Simon A. Mallal, MBBS, Peggy L. Kendall, MD
Rationale: A fundamental knowledge gap exists regarding genetic causes of peanut allergy (PA).  Large genetic databases now make it possible to conduct detailed human genome studies to identify contributors to disease. 

Methods: BioVU, a unique biorepository of >200,000 DNA samples matched to de-identified electronic medical records (EMR), was used to identify subjects for study of HLA alleles associated with peanut allergy (PA).  65 PA patients and 170 peanut tolerant controls (PC) were identified in BioVU using an algorithm ratified by expert review.  Of these, 16 PA and 43 PC self-identified White patients had genotypic data available for analysis.  HLA alleles were imputed from Illumina® HumanExome BeadChip data using SNP2HLA.  HLA allele associations were tested in a dominant model with PLINK with significance considered at alpha=0.05.

Results: No significant associations (p<0.05) were detected.  Suggestive associations included HLA-DQB1*05*02 (p=0.07, OR 1.25), which correlated with increased risk of PA, and HLA A*68 (p=0.10, OR 0.70), which correlated with decreased risk of PA. 

Conclusions: The trend in HLA-DQ associating with PA risk conforms with previous studies localizing risk to the HLA class II HLA-DR/DQ region.  HLA sequencing amongst all PA and PC will be performed to increase the power to detect associations within the HLA locus. The BioVU repository has provided: 1. A novel platform for studying genetic contributions to PA with the goal of creating a model to define its specific immunopathogenesis and 2. An algorithm for a specific PA phenotype that can now be validated across a large network of EMRs with DNA repositories.