P6017 A high density genome-wide scan for genetic risk factors of insect bite hypersensitivity (IBH): A Horsegene Project Initiative. (1st September 2016)

• Record Type: Journal Article
• Authors: Velie, B. D.; Shrestha, M.; Francois, L.; Schurink, A.; Stinckens, A.; Blott, S.; Ducro, B. J.; Mikko, S.; Thomas, R.; Sundquist, M.; Eriksson, S.; Buys, N.; Lindgren, G.
• Is Part Of: Journal of animal science. Volume 94(2016)Supplement 4
• Page Start: 156
• Page End: 157
• Publication Date: 2016-09-01
• Subjects: allergy -- exmoor -- horse; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.2527/jas2016.94supplement4156a
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: Insect bite hypersensitivity (IBH), a common allergic skin disease in horses caused by biting midges, has been estimated to affect as much as 60% of some breed populations. The result of both genetic and environmental factors, IBH is pruritic and can lead to extensive scratching followed by hair loss, self-excoriation, and skin thickening. Previous studies on IBH suggest both common and breed specific genomic regions associated with IBH. As such, breed specific information regarding the genetic mechanisms involved in IBH development is needed to enable efficient and accurate selection against IBH across multiple breeds. The current study uses Exmoor ponies, a highly inbred breed of horse known to frequently suffer from insect bite hypersensitivity, to identify genomic regions associated with this type I and type IV hypersensitive reaction. A total of 110 cases and 170 controls were genotyped on the 670K Axiom Equine Genotyping Array. Quality control resulted in 452, 457 SNPs and 268 individuals being tested for association. Genome-wide association analyses were performed using the GenABEL package in R and resulted in the identification of two regions of interest on Chromosome 8. The first region contained the most significant SNP identified, which was located in an intron of the DCC netrin 1 receptor gene. The second region identified contained multiple top SNPs and encompassed the PIGN, KIAA1468, TNFRSF11A, ZCCHC2, and PHLPP1 genes. While the region consists of five genes, TNFRSF11A stands out as a potential candidate gene. Not only is TNFRSF11A the closest gene to SNP AX-104330407, but screening for TNFRSF11A has already been suggested as a potential diagnostic test for autoinflammatory disorders in humans. At the meeting, we will present the results of our genome-wide association analyses and provide additional information on the frequencies of the top SNPs in other IBH prone breeds.