Genetics of upper and lower airway diseases in the horse.

This research article explores the role of genetics in equine upper and lower airway diseases, including the environmental factors interacting with genetics in the development of these diseases. It suggests that these diseases are polygenic in nature and single gene testing may not be beneficial in their diagnosis.

Genetic Predispositions in Equine Airway Diseases

• The research starts with an acknowledgment of documented genetic predispositions for certain diseases affecting the airway of horses, like guttural pouch tympany, recurrent laryngeal neuropathy, and recurrent airway obstruction (RAO).
• These diseases are confirmed to have a genetic component, contributing to their occurrence in horses. It is also reported that exercise-induced pulmonary haemorrhage and infectious diseases of the respiratory tract can be influenced by the genetic makeup of the horse.

Interaction of Environment and Genetics

• The study points out the complex dynamics between the environment and the genetic makeup of horses in the clinical manifestation of the airway diseases.
• The determining genetic factors are said to originate from variations in multiple genes, hence classifying the diseases as polygenic.
• Due to their polygenic nature, the study states that single gene tests may not find much use in the diagnostic process of these diseases.

Importance and Limitations of Genetic Profiling

• The article highlights the potential value of genetic profiling panels that integrate multiple genetic factors and an evaluation of environmental risk factors. This may give a more comprehensive view of a horse’s risk of developing airway diseases.
• However, it also mentions the current limitation, which is the lack of sufficient knowledge about the genetic markers and causative variants implicated in equine respiratory diseases. Thus, more research is required to identify these.

Identified Associations and Future Research

• While there are limitations, the study does elucidate some progress in this field. Chromosomal regions associated with guttural pouch tympany, recurrent laryngeal neuropathy, and RAO have been identified.
• The review also emphasises the need for further research as it mentions the associated study of RAO with other hypersensitivities and resistance to intestinal parasites.
• The article serves as a review paper with an objective to compile available data and current findings on the genetics of equine airway diseases and set the stage for future investigations.