We report a patient with necrotizing encephalomyelopathy (Leigh's synd
rome) associated with a deficiency of pyruvate dehydrogenase complex a
ctivity. The underlying mutation is an A to C transversion in the pyru
vate dehydrogenase complex E1alpha subunit gene. As the E1alpha subuni
t is encoded on the X chromosome, this observation confirms that some
patients with Leigh's syndrome may potentially exhibit X-linked inheri
tance.