Lipid myopathy associated with renal tubular acidosis and spastic diplegiain two brothers

Lipid myopathy is a group of disorders involving mitochondrial fatty acid o xidation. We describe two brothers, 3 years 8 months old and 2 years 9 mont hs old, respectively, with progressive spastic diplegia, developmental dela y, failure to thrive, and chronic metabolic acidosis who had lipid myopathy and renal tubular acidosis. Brain magnetic resonance imaging revealed demy elinating changes ill the periventricular white matter, which was compatibl e with spastic diplegia. These symptoms may be related to errors in fatty a cid metabolism. Cerebral palsy had been misdiagnosed in both of these patie nts at another hospital. Therefore, for patients with late-onset and progre ssive spastic diplegia, detailed investigations for underlying diseases are warranted.