Mutations in the gene for the E1beta subunit: a novel cause of pyruvate dehydrogenase deficiency.

[pyruvate dehydrogenase deficiency]

We describe two unrelated patients with pyruvate dehydrogenase (PDH ) deficiency attributable to mutations in the gene encoding the E 1 beta subunit of the complex . This is a previously unrecognised form of PDH deficiency , which most commonly results from mutations in the X-linked gene for the E 1 alpha subunit . Both patients had reduced immunoreactive E 1 beta protein and both had missense mutations in the E 1 beta gene . Activity of the PDH complex was restored in cultured fibroblasts from both patients by transfection and expression of the normal E 1 beta coding sequence .