G6PD and hyperinsulinemic hypoglycemia, familial, 4: We report a male infant with normal early motor development who initially presented at nine months of age with fever, dark urine, elevated transaminases, and markedly increased serum creatine kinase (CK) levels, which were initially attributed to hemolysis and presumed as viral myositis in the context of glucose-6-phosphate dehydrogenase deficiency.