[Skip to Content]
[Skip to Content Landing]
September 1976

Dominant Inheritance of McArdle Syndrome

Author Affiliations

From the Neuromuscular Unit, Department of Neurology, Los Angeles County University of Southern California Medical Center. Dr Munsat is now with the Department of Neurology, TUFTS-New England Medical Center, Boston.

Arch Neurol. 1976;33(9):636-641. doi:10.1001/archneur.1976.00500090042008

• Myophosphorylase deficiency (McArdle syndrome) is an uncommon condition characterized by exercise intolerance, muscle cramping, and myoglobinuria. Although the original report by McArdle1 dealt with a sporadic case, subsequent cases reported in the literature show high familial incidence and consanguinity, implying that the defect is transmitted as a rare recessive gene or a possible sexlimited mode of inheritance. The present report describes the clinical, histoenzymatic, and biochemical findings in a 40-year-old woman with myophosphorylase deficiency. The family history reveals that four other members are also affected: an older sister, a younger brother, a 10-yearold son, and her 75-year-old mother, and possibly her maternal grandmother. Because of this particular pattern of direct transmission in this family, a dominant inheritance is postulated.