Mild Phenotype Associated with SLC6A1 Gene Mutation: A Case Report with Literature Review.

The Solute Carrier Family 6 Member 1 (SLC6A1) gene encodes the gamma-aminobutyric acid (GABA) transporter 1, which is one of the main GABA transporters. The clinical picture of SLC6A1 gene mutations is characterized by a broader spectrum including a mild-to-moderate intellectual disability, speech difficulties, behavioral problems, epilepsy (often with myoclonic-atonic and atypical absence seizures, characterizing a myoclonic-atonic epilepsy), and neurological signs. We describe a boy with an SLC6A1 mutation and a milder phenotype, characterized by a learning disorder without intellectual disability, nonspecific dysmorphisms, and an electroencephalogram picture closely resembling that of myoclonic-atonic epilepsy with brief absence seizures that have appeared during the follow-up, responsive to valproic acid.