Allele frequency of muscular genetic disorders in Bull-Catching (vaquejada) Quarter Horses.

This research focuses on the investigation of the frequency of specific muscular genetic disorders in a type of athletic horse used in a Brazilian equestrian sport, Vaquejada. The disorders studied include myosin-heavy chain myopathy, polysaccharide storage myopathy, hyperkalemic periodic paralysis and malignant hyperthermia.

Introduction to the Study

• This research intends to investigate the allele frequencies of muscular genetic disorders in Quarter Horses (QH), a prominent athletic breed in Brazil, predominantly used in the equestrian sport of bull-catching or vaquejada.
• The genetic disorders of interest are myosin-heavy chain myopathy (MYHM), polysaccharide storage myopathy (PSSM1), hyperkalemic periodic paralysis (HyPP), and malignant hyperthermia (MH).
• The study highlights its importance by mentioning that there was previously no data available regarding the frequency of these genetic disorders in QH used for vaquejada.

Methodology

• The research focused on a specific geographic population, including 129 QH vaquejada athletes from the Northeast region of Brazil.

Research Outcomes

• The results showed heterozygosity, meaning that only one allele carries the disease while the corresponding allele on the other chromosome does not.
• The MYHM disorder was found to have the highest frequency among the sampled horses, with an allele frequency of 0.04 ±0.01.
• The PSSM1 disorder exhibited a frequency of 0.01 ±0.01, and the HyPP disorder showed an allele frequency of 0.004 ±0.01.
• The study reported no occurrences of the disease variant MH in the studied population.

Conclusion and Implication

• The study marks the first identification of these genetic disorder variants in vaquejada QH, highlighting the essential need to guard against potential disease spread.
• The researchers suggest implementing measures to prevent the transmission of pathogenic alleles and thereby lower the incidence of clinical cases of these muscular genetic disorders.