GABA-transaminase deficiency is a brain disease (encephalopathy) that begins in infancy. Babies with this disorder have recurrent seizures (epilepsy), uncontrolled limb movements (choreoathetosis), exaggerated reflexes (hyperreflexia), weak muscle tone (hypotonia), and excessive sleepiness (hypersomnolence). Affected babies may grow faster in length than usual (accelerated linear growth), even though they have feeding problems and may not gain weight as quickly as expected (failure to thrive).

GABA-transaminase deficiency is caused by mutations in the ABAT gene, which provides instructions for making the GABA-transaminase enzyme. This enzyme helps break down a brain chemical (neurotransmitter) called GABA when it is not needed. GABA normally helps slow down (inhibit) brain cell activity when necessary, to prevent the brain from being overloaded with too many signals. For this reason, GABA is called an inhibitory neurotransmitter.

GABA-transaminase deficiency is a very rare disorder. Only a small number of affected individuals have been described in the medical literature.

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Published Date: April 01, 2018
Published By: National Institutes of Health