PROTOCOL OUTLINE: This is a randomized, double blind, crossover study. Patients are stratified according to age (3 months to 2 years vs over 2 to 18 years).

All patients receive at least 12 months of sodium dichloroacetate (DCA) during a 2 year period of double blind, crossover evaluation of DCA and placebo by mouth.

Quality of life is assessed before treatment and periodically during treatment.

PROTOCOL ENTRY CRITERIA:

--Disease Characteristics--

Diagnosis of congenital lactic acidosis (CLA) meeting the following criteria: Three basal venous lactates at least 2.5 mM, arterial lactates at least 2.0 mM, or CSF lactates at least 2.5 mM OR any combination of these, obtained over at least 1 month and within 6 months OR Increase in blood lactate at least 1.0 mM over basal following a carbohydrate meal challenge

AND

Enzymatic or molecular genetic proof of a defect of pyruvate dehydrogenase complex, one or more respiratory chain enzymes, or a Krebs cycle enzyme OR Over production of C14-lactate from C14-glucose by cultured skin fibroblasts

AND

Ability to withstand an 8 hour (if 2 years and under) or 12 hour (if over 2 years) fast without developing hypoglycemia (blood glucose less than 50 mg/dL)

No secondary lactic acidosis due to impaired oxygenation or circulation

No hyperlactatemia associated with proven biotinidase deficiency (biotin responsive CLA) or with enzyme deficiencies of gluconeogenesis

No primary, defined organic acidurias other than lactic acidosis, for which effective therapy is available (e.g., propionic aciduria)

No primary disorders of amino acid metabolism or fatty acid oxidation

No malabsorption syndromes associated with D-lactic acidosis

--Prior/Concurrent Therapy--

No chronic dialysis

--Patient Characteristics--

Hepatic: No primary hepatic disease unrelated to CLA

Renal: Creatinine less than 1.2 mg/dL OR Creatinine clearance at least 60 mL/min

Other: No concurrent infection or fever