Summary

Despite the majority of patients with McArdle disease reporting symptoms including fatigue, cramps and episodes of myoglobinuria from early childhood, diagnosis is often delayed by several decades. Additionally, many individuals with rhabdomyolysis remain undiagnosed. The occurrence of symptoms during exercise, particularly isometric muscle contraction such as heavy lifting, is well known in McArdle disease. However, isometric muscle contraction that occurs with emotion is not recognised as exercise and may be missed as a trigger for rhabdomyolysis, potentially leading to a delay in diagnosis. Three patients are presented here, all with symptoms from childhood including episodes of rhabdomyolysis induced by tense emotional situations without physical exertion; two patients reported recurrent episodes while watching rather than playing football. The remaining patient developed rhabdomyolysis during a heated argument. These patients’ histories emphasise the risk from sustained isometric muscle contraction that occurs in emotive situations for patients with McArdle disease.