Authors: Bindi, Veronica Eiroa, Hernan
Hospital Juan P. Garrahan Buenos Aires, Argentina
Very long-chain acyl-coenzyme A dehydrogenase deficiency (VLCADD) is an autosomal recessive metabolic disorder that affects mitochondrial fatty acid b oxidation, that can impacts in heart, liver and muscle function.
We aimed to explore the clinical, biochemical and nutritional findings of a challenging case.
A male was born at term with birth weight of 3100 grams by vaginal delivery to a 35 year-old mother. Pregnancy, prenatal labs and ultrasound were unremarkable. Delivery was uncomplicated. Infant was discharged home on third day of life.
The child’s family history showed two death siblings before the diagnosis was made. Cause or death was reported as mitochondrial cardiomyopathy. The diagnosis was made by acylcarnitines analysis performed in dried blood spots that were saved.
At two weeks of life, the baby became lethargic with poor feeding and dehydration. The infant was admitted to the intensive care unit for rehydration and sepsis evaluation. Biochemical findings showed hypoglycemia, hyperlactacidemia and acidosis. Cardiac evaluations showed mild hypertrophy cardiomyopathy.
Because of family history and following symptoms we analyzed baby´s acylcarnitines profile and organic acids. Initial plasma acylcarnitine concentrations were indicative of a VLCADD diagnosis and decreased with treatment.
It showed C14:1 and C14 elevations: C14 15, 1 μmol/L(1,6-16), C14:1 0.51 μmol/L (<0,24) high ratio C14:1/C2 0,19 ( <0,05) and dicarboxylic aciduria. Molecular DNA testing for ACADVL is still pending.
Nutritional treatment was sustained on MCT based formula with additional MCT oil 1grams/kilo/day. Total calories intakes were around 2000-2500 kcal/day and the distribution of energy was: 18% as protein, 58% as carbon hydrates and 24% as fat. The fat’ distribution was 18% medium chain and 6% long chain.
Supplementation with L-carnitine is subject to plasma levels.
The numbers of admissions were increased with years: varied from 1 to 4 episodes, with an average of 3 per year. Before 2 years, biochemical findings were hypoglycemia and acidosis.
After two years old, the causes of admissions were rhabdomyolysis sometimes with renal impairment. He presented with severe rhabdomyolysis during exercise or increased of catabolism. Most of them without a known trigger. Once he required renal replacement with hemodialysis. He required gastrostomy placement and porth a cath due to frequents admissions.
Nowadays, he´s 8 years old and his cardiac function is normal. He tolerates 3 hours of fasting during the day and continues gastric feeding at night. He´s restricted in his physical activity. Its anthropometric measurements reveal obesity (+5,6DS) and normal height (+2 DS). He has normal cognitive outcome.
The importance of early diagnosis of undiagnosed cases of fatty acid oxidation defects might avoid symptomatic hypoglycemia or sudden unexplained death. The family of our reported case had lost two previous children due to VLCAD deficiency; in this report, the patient’s condition was fortunate to have been recognized early.
In Argentina neonatal screening for fatty acid oxidation disorders is not available.
We saw rapid response to high concentration of MCT-based feeding formula. With growing he developed a myopathic form with a high risk of renal failure/ chronic disease.
Despite adequate dietary treatment and exercise restriction, episodes of rhabdomyolysis persist. Sometimes there is no trigger during events. Other therapeutic strategies should be taken into account to improve their quality of life.