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.

Abstract

We investigated whether or not elevated whole blood dodecanoic acid concentration was due to a beta-oxidation defect in fatty acid metabolism previously reported. We prospectively analyzed blood from 55 consecutive sudden infant death syndrome (SIDS) cases for fatty acid concentrations by gas chromatograph. Three of 55 cases had elevated dodecanoic acid concentrations (> or = 18.4 mg/L). The three SIDS cases with elevated blood dodecanoic acid were confirmed to have medium chain acyl-CoA dehydrogenase (MCAD) deficiency by outside laboratories, indicating that elevated dodecanoic acid is highly specific and sensitive for predicting MCAD deficiency in SIDS victims. Dodecanoic acid was easily detected in routine toxicology for acid and neutral drugs done at autopsy. MCAD deficiency is an autosomal recessive genetic disease, carrying a 25% recurrence risk. Families should be notified that siblings, both presently living and yet to be born, should be screened for this deficiency because MCAD deficiency can be treated, and sudden, unexplained infant deaths of living and subsequent offspring can be prevented.