The gene for the alpha polypeptide of pyruvate dehydrogenase is X-linked in humans.

The chromosomal location of the gene for the alpha polypeptide of the pyruvate dehydrogenase (alpha E1), a major component of the pyruvate dehydrogenase complex, was determined by using a cloned cDNA for alpha E1. This 1-kb cDNA was isolated from a human liver lambda gt11 expression library with specific antibodies and included the coding (from amino acid 144 to the carboxy terminus) and the 3' untranslated regions. Southern blot analysis of the DNA from a panel of rodent-human hybrid cells showed that the absence or the presence of the major EcoRI fragment that hybridized with this cDNA probe was concordant with the presence of the Xq24-p22 region of the human X chromosome. The result of in situ hybridization with human metaphase chromosomes further mapped the alpha E1 gene to the Xp arm.