Fumarase catalyzes the conversion of fumarate to malate in the Krebs cycle. Fumarase deficiency is a rare inborn error of metabolism and is inherited in an autosomal recessive manner. It causes mitochondrial encephalomyopathy. The symptom is characterized by developmental delay and hypotonia.

We report here a case of a 32-month-old child who was initially refered because of spastic quadriplegia, delayed development and poor feeding.