Attributive and in the genitive. Designating an inherited (autosomal recessive) disorder of skeletal muscle in which deficiency of the enzyme glycogen phosphorylase results in an inability to metabolize glycogen to lactate, leading to exercise intolerance, muscle cramps and weakness, and intermittent myoglobinuria.
1950s. From the name of Brian McArdle (b. 1911–2002), British physician who identified the disease in 1951 (Clin. Sci 10 13).