WHOLE-BLOOD LEVELS OF DODECANOIC ACID, A ROUTINELY DETECTABLE FORENSIC MARKER FOR A GENETIC-DISEASE OFTEN MISDIAGNOSED AS SUDDEN-INFANT-DEATH-SYNDROME (SIDS) - MCAD DEFICIENCY

We investigated whether or not elevated whole blood dodecanoic acid co ncentration was due to a beta-oxidation defect in fatty acid metabolis m previously reported. We prospectively analyzed blood from 55 consecu tive sudden infant death syndrome (SIDS) cases for fatty acid concentr ations by gas chromatograph. Three of 55 cases had elevated dodecanoic acid concentrations (greater than or equal to 18.4 mg/L). The three S IDS cases with elevated blood dodecanoic acid were confirmed to have m edium chain acyl-CoA dehydrogenase (MCAD) deficiency by outside labora tories, indicating that elevated dodecanoic acid is highly specific an d sensitive for predicting MCAD deficiency in SIDS victims. Dodecanoic acid was easily detected in routine toxicology for acid and neutral d rugs done at autopsy. MCAD deficiency is an autosomal recessive geneti c disease, carrying a 25% recurrence risk. Families should be notified that siblings, both presently living and yet to be born, should be sc reened for this deficiency because MCAD deficiency can be treated, and sudden, unexplained infant deaths of living and subsequent offspring can be prevented.