Pyruvate Dehydrogenase E1-Beta Deficiency

Pyruvate dehydrogenase (PDH) deficiency is a highly heterogeneous disorder that is one of the major causes of severe primary lactic acidosis in the newborn period and infancy. It can also present as a more chronic neurodegenerative disease with extensive cerebral atrophy and structural anomalies in the brain, as Leigh syndrome or as episodic ataxia. Antenatally, neurodevelopmental lesions, and craniofacial dysmorphisms may be present. The majority of cases of PDH deficiency (~60% to >80%) are due to pathogenic variants in the PDHA1 gene that encodes the pyruvate dehydrogenase E1 α-subunit (see separate information sheet for details on PDHA1 gene analysis). A very rare cause of PDH deficiency is due to variants in the PDHB gene, that encodes the E1-beta subunit of pyruvate dehydrogenase. Features of PDH deficiency due to variants in the PDHB gene are similar to those seen in individuals with PDHA1 deficiency except that ataxia appears to be more frequent in PDHA1 cases. Consanguinity is more common in the families with PDHB gene variants.

Tests Available

Forms and Documents

Test Details

PDHB
  • Confirmation of biochemical diagnosis
  • Carrier testing
  • Prenatal diagnosis in at risk pregnancies
  • Capillary Sequencing

Ordering

462
4-5 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

81405x1
No
Yes
  • 276.2 Acidosis Acidosis
  • 277.87 Disorders of mitochondrial metabolism, Kearns-Sayre syndrome, Mitochondrial Encephalopathy, Lactic Acidosis and Stroke-like episodes (MELAS syndrome), Mitochondrial Neurogastrointestinal Encephalopathy syndrome (MNGIE), Myoclonus with Epilepsy and with Ragged Red Fibers (MERRF syndrome), Neuropathy, Ataxia and Retinitis Pigmentosa (NARP syndrome)
  • 330.8 Other specified cerebral degenerations in childhood, Alpers' disease or gray-matter degeneration, Infantile necrotizing encephalomyelopathy, Leigh's disease, Subacute necrotizing, encephalopathy or encephalomyelopathy
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References

  1. Brown et al. (2006) Dev Med Child Neurol 48 (9):756-60 (PMID: 16904023)
  2. Okajima et al. (2008) Mol. Genet. Metab. 93 (4):371-80 (PMID: 18164639)
  3. Imbard et al. (2011) Molecular Genetics And Metabolism 104 (4):507-16 (PMID: 21914562)
  4. Stenson et al. (2014) Human Genetics 133 (1):1-9 (PMID: 24077912)
  5. Pirot et al. (2016) J. Neuropathol. Exp. Neurol. 75 (3):227-38 (PMID: 26865159)