Blog

A team of researchers at the University of Minnesota and the University of California, Davis, have published a landmark study of the predicted genetic burden in horses, based on the analysis of whole genome sequence data from 605 horses (1). They conclude that the genetic load in horses is 1.4 – 2.6 times that of the human population. The authors discuss the unique advantages of the study of horse to understand human phenotypes, especially those associated with athletic performance.

Horse owners have asked us to explain this paper, as it mentions the genetic variants that are in EquiSeq’s panel of DNA tests. Here we review the methods and major findings of this paper. We include background information typically absent from the primary literature in order to make the paper more accessible to non-specialists.

Polysaccharide Storage Myopathy (PSSM) is a form of equine exercise intolerance characterized by episodes of tying up. Horses with this condition have a particular set of clinical signs, including displays of pain, refusal to move forward, trouble standing for the farrier, and standing “parked out” as if to urinate. All of these are signs of…

How can you figure out the chances of different genotypes when breeding horses? Monohybrid Cross It’s easy for one gene. Let’s say that there is a stallion that has one copy of one of the genetic variants associated with PSSM2, the P2 variant (MYOT-S232P). This stallion is heterozygous (n/P2), meaning that he has one normal…

Contents Introduction The K1 genetic variant that has been part of EquiSeq’s Myopathy Panel since October 2019 is a missense allele of COL6A3, a gene encoding a collagen [1]. Collagens are a family of proteins that are the main structural components of the connective tissue. Collagens also guide bone formation and play an important role in…

This blog post is a discussion of a paper published by Williams et al. in a recent issue of Equine Veterinary Journal [1]. The paper aims to identify genetic variants that might be responsible for Myofibrillar Myopathy (MFM) in Warmbloods. The authors use a candidate gene approach, searching for variants of eight of the nine genes known…

Paul Szauter, PhD, Chief Scientific Officer of EquiSeq, gave a presentation titled “Genetic Basis of Exercise Intolerance in Arabians” at the Al Khamsa Annual Meeting and Convention in Fayetteville, Arkansas on October 13, 2019. EquiSeq is a company based in Albuquerque, New Mexico, that develops and sells genetic tests for horses. Exercise intolerance is known…

A Genome Wide Association Study (GWAS) of Recurrent Exertional Rhabdomyolysis (RER) identified a region on chromosome 16 as the only part of the genome associated with RER [1]. One of the populations in the study showed an association between RER and five Single Nucleotide Polymorphisms (SNPs) that define a 71.6 kb interval within the 822…

Several recent studies address the mechanism of muscle damage in filaminopathy. Filaminopathy is a term that describes muscle disorders resulting from mutations in the FLNC gene, which encodes filamen C. Two different clinical disease states are included in filaminopathy: Myofibrillar Myopathy 5 (MFM5) and Distal Myopathy 4 (DM4). Studies on the mechanism of muscle damage in filaminopathy…

How can you figure out the chances of different genotypes when breeding horses? Monohybrid Cross It’s easy for one gene. Let’s say that there is a stallion that has one copy of one of the genetic variants associated with PSSM2, the P2 variant (MYOT-S232P). This stallion is heterozygous (n/P2), meaning that he has one normal…