[Five cases of phosphorylase b kinase deficiency affecting muscle or liver: clinical symptoms and diagnosis].

Muscle, erythrocyte and/or leukocyte phosphorylase b kinase (PBK) activities were measured in 5 patients and in 2 families. The relation between phenotype and enzyme deficiency in clinically variable samples based on measurement of erythrocytes, leukocytes or muscle was described. Three patients showed the enzyme deficiency in liver and the disease was transmitted as an X-linked recessive trait. In these cases, our results suggested that carrier detection was more reliable with erythrocytes than leukocytes. Two patients showed enzyme deficiency in muscle, and the mode of inheritance was not clear. In these cases, muscle biopsies were necessary for diagnosis.