Equine clinical genomics: A clinician's primer

Abstract

Summary The objective of this review is to introduce equine clinicians to the rapidly evolving field of clinical genomics with a vision of improving the health and welfare of the domestic horse. For fifteen years a consortium of veterinary geneticists and clinicians has worked together under the umbrella of The Horse Genome Project. This group, encompassing 22 laboratories in 12 countries, has made rapid progress, developing several iterations of linkage, physical and comparative gene maps of the horse with increasing levels of detail. In early 2006, the research was greatly facilitated when the U.S. National Human Genome Research Institute of the National Institutes of Health added the horse to the list of mammalian species scheduled for whole genome sequencing. The genome of the domestic horse has now been sequenced and is available to researchers worldwide in publicly accessible databases. This achievement creates the potential for transformative change within the horse industry, particularly in the fields of internal medicine, sports medicine and reproduction. The genome sequence has enabled the development of new genome-wide tools and resources for studying inherited diseases of the horse. To date, researchers have identified eleven mutations causing ten clinical syndromes in the horse. Testing is commercially available for all but one of these diseases. Future research will probably identify the genetic bases for other equine diseases, produce new diagnostic tests and generate novel therapeutics for some of these conditions. This will enable equine clinicians to play a critical role in ensuring the thoughtful and appropriate application of this knowledge as they assist clients with breeding and clinical decision-making.

Single nucleotide polymorphisms associated with osteochondrosis dissecans in Warmblood horses at different stages of training

“…Many other traits have been studied, but in most cases without identification of the causal mutation. A better understanding of the genetic background underlying equine diseases is of special importance, particularly if the disease is as common as the hereditary equine regional dermal asthenia; the prevalence of the mutation is as high as 30% in some horse lines and up to 50% of national populations (Brosnahan et al 2010). The problem of identifying the genes responsible for diseases is even more complicated for traits with a complex or pure polygenic mode of inheritance.…”

Host genetic influence on papillomavirus‐induced tumors in the horse

“…Compared with common model organisms and most domestic livestock, the horse has a longer lifespan (20–30 years) which permits the development and expression of several chronic diseases . Determination of the genetic basis for equine Severe Combined Immunodeficiency Disease and equine Congenital Stationary Night Blindness has been important to the understanding of related human conditions.…”

The Role of Genomics in Conservation and Reproductive Sciences

“…Other areas of comparative genomic research, such as among normal and diseased tissues will also provide a synergistic approach of study that will assist in the management of inherited diseases through improved diagnosis and therapies (e.g. in horses as in Rosnaha et al 2010 ). Finally, comparative genomic techniques and the application of metagenomic technologies and approaches to the study of whole "ecosystems" or biomes, such as the NIH Human Microbiome project, will also provide insights on the range of functional and abnormal systems and the role of microbiota in diverse settings such as in reproductive systems (Aagaard et al 2012 ).…”