A case of early diagnosed carnitine deficiency presenting with respiratory symptoms

摘要

INTRODUCTION: Carnitine deficiency is an autosomal recessively inherited disease characterized by a low carnitine concentration in plasma and tissues. Primary carnitine deficiency (PCD) is caused by a deficiency in the plasma membrane carnitine transporter, with urinary carnitine wasting causing systemic carnitine depletion. The most common presentation of PCD is hypoketotic hypoglycemic encephalopathy. Cardiomyopathy can also be seen. CASE REPORT: A 9-month-old girl was admitted to our clinic with wheezing, respiratory distress and nighttime cough. She was pale, expirium was prolonged, breath sounds were coarse bilaterally and were increased in the right hemithorax. RESULTS: She had hypochromic microcytic anemia and the serum CPK level was elevated. Cardiothoracic index was increased (0.62). In the chest X-ray there was hyperaeration especially in the upper regions of the left lung, and paracardiac infiltration in the right lung. The echocardiogram showed dilated cardiomyopathy. In pulmonary perfusion scintigraphy, perfusion of the right lung was 26% and of the left lung 74%. Cardiomegaly and dilatation in main the pulmonary artery was detected in the MR angiogram. Plasma carnitine and acylcarnitine levels were found to be significantly low. Fat accumulation in myocytes and rare atrophic fibers were detected in a muscle biopsy. Oral carnitine supplementation was started at a dose of 100 mg/kg. All the symptoms and findings regressed within a short period of time. DISCUSSION: This case was presented to emphasize that carnitine deficiency can present with respiratory tract symptoms like wheezing and recurrent respiratory tract infections. Although PCD usually presents with hypoketotic hypoglycemia in infants, it also has to be suspected in the etiology of dilated cardiomyopathy. Treatment is very easy and lifesaving once the correct diagnosis is made, and the prognosis is excellent with lifelong carnitine supplementation.