Medium-chain acyl-CoA dehydrogenase deficiency and sudden death in two siblings

Medium-chain acylCoA dehydrogenase (MCAD) deficiency is a disorder of fatty acid oxidation whose prevalence in North-Eastern Europe has been estimated at 1/10000 to 1/20000 births. MCAD deficiency can cause sudden death in the first two years of life. Two cases in siblings are reported; both patients died at nine months of age. Case report: A male infant, born to unrelated Caucasian parents, died suddenly at age 9 months during an episode of viral gastroenteritis. Post mortem examination was non contributive, Twenty-one months later, his younger sib, aged 9 months, presented with apparently benign gastroenteritis causing feeding problems. He was admitted several hours later in a coma with severe hypoglycaemia and died shortly afterwards despite ressuscitation. Autopsy showed prominent steatosis in the liver. The study of urinary organic acids and acylcarnitines disclosed pathognomonic profiles consistent with MCAD. The diagnosis was confirmed by DNA analysis showing the specific MCAD mutation G 985 A in a homozygous state in both siblings. The authors emphasize the value of MCAD routine screening in the newborn population, by mutation analysis and/or by blood acylcarnitine profiles. Conclusion. Screening for MCAD is warranted in all infants presenting with severe malaise or unexplained sudden death.