γ-Aminobutyric acid (GABA)-transaminase deficiency is an ultra-rare disorder of GABA metabolism that was described for decades as an early-onset epileptic encephalopathy plus movement disorder and hypersomnolence with mortality in early childhood. We report 2 affected siblings in adolescence and adulthood, both with profound developmental impairment, intractable epilepsy, movement disorder, and behavioral fluctuations. This considerably expands the phenotype and longevity of this inherited neurotransmitter disease.
Keywords: ABAT gene; GABA metabolism; GABA-T deficiency; GABA-transaminase deficiency; India.