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.
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.
Olpin
S E
SE
Neonatal Screening Laboratory, Children's Hospital, Sheffield, UK.
Manning
N J
NJ
Carpenter
K
K
Middleton
B
B
Pollitt
R J
RJ
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000172:deficiency; D002478:Cells, Cultured; D003937:Diagnosis, Differential; D003998:Dicarboxylic Acids / Q000652:urine*; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D063989:Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase; D009227:Myristic Acids / Q000378:metabolism*; D010084:Oxidation-Reduction; D010169:Palmitic Acids / Q000378:metabolism*; D014316:Tritium / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
D003998:Dicarboxylic Acids; D009227:Myristic Acids; D010169:Palmitic Acids; D014867:Water; D014316:Tritium; C033961:tritium oxide; D015094:3-Hydroxyacyl CoA Dehydrogenases; D063989:Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase