[American Quarter Horses and HYPP]

Area of Science:

• Genetics
• Equine Medicine
• Molecular Biology

Context:

• Hyperkalaemic periodic paralysis (HYPP) is a significant inherited condition in American Quarter Horses.
• The disease is linked to a specific mutation in the equine skeletal muscle sodium channel gene (SCN4A).
• This mutation results in episodes of muscle weakness or paralysis.

Purpose:

• To describe the genetic basis of Hyperkalaemic periodic paralysis in American Quarter Horses.
• To explain the diagnostic approach using DNA testing.
• To outline current therapeutic and preventive measures for affected horses.

Summary:

• Hyperkalaemic periodic paralysis (HYPP) is an autosomal dominant genetic disorder in American Quarter Horses.
• A mutation in the gene encoding the skeletal muscle sodium channel causes abnormal muscle excitability and intermittent weakness.
• DNA testing can determine a horse's genotype (homozygous negative, heterozygous, or homozygous positive) for the HYPP mutation.

Impact:

• Facilitates accurate diagnosis and genetic counseling for Hyperkalaemic periodic paralysis.
• Enables informed breeding decisions to reduce the prevalence of HYPP in American Quarter Horses.
• Supports the development of effective management strategies to improve the quality of life for affected horses.