Differential diagnosis of hydroxydicarboxylic aciduria based on release of 3H2O from [9,10-3H]myristic and [9,10-3H]palmitic acids by intact cultured fibroblasts

J Inherit Metab Dis. 1992;15(6):883-90. doi: 10.1007/BF01800227.


Intact cultured fibroblasts from patients with deficiency of long-chain 3-hydroxyacyl-CoA dehydrogenase release 3H2O from [9,10-3H]myristic acid and [9,10-3H]palmitic acid more slowly than normal. The ratio of activity (palmitate/myristate) is also low and the expression (rate with palmitate2/(rate with myristate) gives good differentiation between affected and unaffected cells. In some patients who have shown hydroxydicarboxylic aciduria when unwell there is reduced 3H2O production from [9,10-3H]myristic and [9,10-3H]palmitic acids by intact cultured fibroblasts but normal 3-hydroxyacyl-CoA dehydrogenase activities in disrupted cells. The palmitate/myristate ratio is higher than in long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency. The basic defect in these patients is still unknown but it is suggested that caution be used over the administration of medium-chain triglyceride.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Hydroxyacyl CoA Dehydrogenases / deficiency
  • Cells, Cultured
  • Diagnosis, Differential
  • Dicarboxylic Acids / urine*
  • Fibroblasts / metabolism*
  • Humans
  • Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase
  • Myristic Acids / metabolism*
  • Oxidation-Reduction
  • Palmitic Acids / metabolism*
  • Tritium / metabolism*
  • Water / metabolism*


  • Dicarboxylic Acids
  • Myristic Acids
  • Palmitic Acids
  • Water
  • Tritium
  • tritium oxide
  • 3-Hydroxyacyl CoA Dehydrogenases
  • Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase