Data from: Genome-wide association study of insect bite hypersensitivity in Swedish-born Icelandic horses

Insect bite hypersensitivity (IBH) is the most common allergic skin
disease in horses and is caused by biting midges, mainly of the genus
Culicoides. The disease predominantly comprises a type I hypersensitivity
reaction, causing severe itching and discomfort that reduce the welfare
and commercial value of the horse. It is a multifactorial disorder
influenced by both genetic and environmental factors, with heritability
ranging from 0.16 to 0.27 in various horse breeds. The worldwide
prevalence in different horse breeds ranges from 3% to 60%; it is more
than 50% in Icelandic horses exported to the European continent and
approximately 8% in Swedish-born Icelandic horses. To minimize the
influence of environmental effects, we analyzed Swedish-born Icelandic
horses to identify genomic regions that regulate susceptibility to IBH. We
performed a genome-wide association (GWA) study on 104 affected and 105
unaffected Icelandic horses genotyped using Illumina® EquineSNP50
Genotyping BeadChip. Quality control and population stratification
analyses were performed with the GenABEL package in R (λ = 0.81). The
association analysis was performed using the Bayesian variable selection
method, Bayes C, implemented in GenSel software. The highest percentage of
genetic variance was explained by the windows on X chromosomes (0.51% and
0.36% by 73 and 74 mb), 17 (0.34% by 77 mb), and 18 (0.34% by 26 mb).
Overlapping regions with previous GWA studies were observed on chromosomes
7, 9, and 17. The windows identified in our study on chromosomes 7, 10,
and 17 harbored immune system genes and are priorities for further
investigation.