Aberrant Splicing of Exon 6 in the Pyruvate Denydrogenase-Elα mRNA Linked to a Silent Mutation in a Large Family with Leigh's Encephalomyelopathy

Pyruvate dehydrogenase (PDH)-Elα deficiency has recently been studied at the molecular-genetic level. The gene is situated on the X chromosome. We report on an unusual mutation in a familial Elα deficiency. In fibroblasts, PDH deficiency was diagnosed in a young infant presenting with Leigh's encephalomyelopathy and in a maternal nephew with episodes of “malaises.” In the two affected children as well as their mothers we found a silent mutation in exon 6 of the PDH-Elα and an aberrant splicing of exon 6 in some of the cDNA clones. This case emphasizes the need for both genomic and cDNA analysis in cases where a PDH-Elα deficiency is strongly suspected.