Swine Diagnostic Tests
Porcine stress syndrome (PSS)
Porcine stress syndrome (PSS) is a deleterious genetic condition affecting pigs. In animals that are homozygous for the PSS mutation, stress can lead to muscle contracture, hypermetabolism and acidosis. This condition has a significant economic impact due to increased mortality and inferior quality pork in homozygous animals. The primary cause of PSS has been identified as a single base mutation from C to T in the ryanodine receptor resulting in an arginine to cysteine amino acid substitution. Physiologically, this structural change results in hypersensitivity of the ryanodine receptor to a number of triggering agents, leading to abnormally elevated levels of intracellular calcium ions. Identification of the presence of this genetic abnormality in the heterozygous or carrier state allows the breeder to avoid matings that would increase the prevalence of the abnormality.