What is the most common disorder of lipid metabolism in muscle?
Carnitine palmitoyltransferase 2 deficiency is the most common disorder of lipid metabolism in muscle and a major cause of hereditary recurrent myoglobinuria, which is precipitated by fasting, prolonged submaximal exercise, and fever. It has three phenotypes:
(1) adult myopathic form;
(2) infantile hepatocardiomuscular form, which is life threatening; and
(3) fatal neonatal form, which presents shortly after birth with respiratory distress, seizures, cardiohepatomegaly, dysmorphic features, and neuronal migration deficits.
The adult myopathic form is the most frequent type, and usually has a benign course.
Between episodes of myoglobinuria, muscle strength and serum CK are normal.
