A case of impairment of mitochondrial fatty acid beta-oxidation

We describe a patient with impairment of mitochondrial fatty acid P-oxidation. A Japanese baby boy was delivered in the 38th week of gestation by emergency cesarean section due to fetal asphyxia. His birth weight was 1,985 g (<10th percentile), length 44.8 cm (<10th percentile), and head circumference 31.0 cm (10th percentile). His Apgar scores were 3 and 5 at 1 min and 5 min, respectively. Blood glucose was 12 mg/dl at 1 hour after birth, requiring glucose administration. On day 1 his serum CK was 20,780 IU/l, which was thought to be due to asphyxia. His serum CK levels gradually began to decrease. At 3 months of age, he sucked poorly, had poor body weight gain, and muscle hypotonia was observed. On day 117 his general condition was impaired, and marked hepatomegaly was observed. The blood glucose level was 43 mg/dl. The patient's urine was negative for ketone bodies. His serum triglyceride level was 3,670 mg/dl. Abdominal CT scan revealed a fatty liver. Serum levels of acyl carnitine from very-long chain fatty acid increased. On day 118 he died due to ventricular fibrillation. On necropsy, massive lipid deposition was observed in the liver, cardiac muscle, kidney, skeletal muscle, and intestinal mucosa. The ratio of very-long chain acyl-CoA dehydrogenase (VLCAD) activity for C16/C8 fatty acid was 0.50 (normal control 1.29), suggesting abnormal VLCAD. He was diagnosed as having impairment of mitochondrial fatty acid beta-oxidation, presumably due to the VLCAD deficiency.