Pyruvate dehydrogenase complex deficiency (PDCD) is a rare congenital disorder of metabolism. Pyruvate dehydrogenase complex converts pyruvate to acetyl-CoA, which is necessary for cellular energy production. PDCD is usually inherited in an X-linked dominant manner but can also be of autosomal recessive inheritance.

Clinical features of this disorder are highly variable. In the severe early infantile form, infants typically present in the first days of life with hypotonia, feeding difficulty, lethargy, lactic acidosis, and respiratory distress. Seizures are not uncommon. Patients with PDCD often have congenital anatomic abnormalities, such as agenesis of the corpus callosum and dysmorphic features (eg, frontal bossing, broad nasal bridge, upturned nose, micrognathia, low-set ears, hypospadias, short fingers and arms). Other infants may present in infancy (3-6 months) with hypotonia, feeding difficulty, and developmental delay. These infants often experience a progressive decline including dystonia, optic atrophy, ophthalmoplegia, and seizures, consistent with Leigh syndrome. A more benign thiamine-responsive, late infantile form with fluctuating ataxia has been reported.