A genome-wide association study for equine recurrent airway obstruction in European Warmblood horses reveals a suggestive new quantitative trait locus on chromosome 13.

The research article investigates the genetic factors contributing to recurrent airway obstruction, an asthma-like respiratory disease in horses, and suggests a new genetic locus on chromosome 13 that might be influential.

Overview of the Study

• This research focuses on Recurrent airway obstruction (RAO), a respiratory disease, similar to human asthma, that affects horses. This disease’s development is influenced by environmental factors, such as exposure to moldy hay or straw bedding, and indoor stabling.
• While prior studies have indicated a hereditary component to RAO, no defined genetic variant has been discovered that impacts the horse’s risk of acquiring the illness.
• The researchers in this study revisited an existing dataset and selected 384 horses for genotyping using the Affymetrix high-density equine SNP array. This process allowed them to search for potential genetic variants associated with RAO.

Genome-wide Association Study Findings

• An allelic case-control genome-wide association study was performed. This method aims to identify specific genetic variants that occur more often in individuals with a particular condition (in this case, RAO) than in those without it.
• The study revealed a significant association on chromosome 13 at a specific location (32,843,309 bp). The identified Single-nucleotide polymorphism (SNP) is situated within the TXNDC11 gene.

Implications and Future Research Directions

• In terms of biochemical function, TXNDC11 has been found to potentially be involved in the folding process of DUOX1 and DUOX2 multiprotein complexes. These proteins regulate the production of hydrogen peroxide in the respiratory tract epithelium and the expression of MUC5AC mucin in humans. Such processes could be correlated with respiratory diseases.
• These findings suggest that TXNDC11 could play a role in the manifestation of RAO in horses, marking it as a functional candidate gene for further investigation.
• The authors highlight the necessity for further studies to understand the potential role of TXNDC11 in horses affected by RAO and to verify its relevance to the disease.