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Paediatric Laboratory Medicine

Pyruvate Dehydrogenase - Total Enzyme Activity

Clinical Significance

To measure the total activity of pyruvate dehydrogenase.

Test Name

Pyruvate Dehydrogenase - Total Enzyme Activity

Alternate Name/ Synonym

PDH - Total

Gene Name

  • This test can identify deficiencies of E1, E2, E3, E3BP and PDP1 (caused by mutations in PDP1, OMIM #608782)


Mitochondrial Disease


Radioactive assay (1-14C Pyruvate)

Turn Around Time

Fibroblasts: 3 weeks - 3 months;


  • Leigh's
  • Microcephaly
  • Developmental Delay

Specimen Type

Suspensions from fibroblast, amniocytes and lymphoblast cell cultures.

Minimum Specimen Requirements

1 dish of cells. *Note: A maximum of 8 cell lines (7 patients and 1 control) can be processed in one run.

Optimal Collection Time

Start in the morning ASAP (assay is time consuming and usually takes whole day).


Cell are kept in TC incubator prior to assay

Special Requirements

This is a radioactive assay and all safety measures required for work with radioactive materials should be strictly observed.

Shipping and Contact Information

The Hospital for Sick Children
Rapid Response Laboratory
170 Elizabeth Street, Room 3642
Toronto, ON
M5G 2G3
Phone: 416-813-7200
Phone: 1-855-381-3212

Reference Range

Fibroblasts, Lymphoblasts:

  • PDH Native: 0.46-1.60 nmoles/min/mg protein
  • PDH Dichloroacetate Activated: 0.87-2.33 nmoles/min/mg protein

Note: Very sensitive assay and there will be variations in the replicate samples.


A PDH deficiency should be suspected in newborn or older children with various neurological symptoms, increased lactate and pyruvate levels in serum and CSF, low to normal L/P ratio, and an increased level of alanine in serum.