Gm2-Gangliosidosis, Ab Variant, also known as hexosaminidase activator deficiency, is related to gm1 gangliosidosis and gangliosidoses, and has symptoms including hyperacusis, seizures and abnormal pyramidal signs. An important gene associated with Gm2-Gangliosidosis, Ab Variant is GM2A (Ganglioside GM2 Activator), and among its related pathways/superpathways are Metabolism and Diseases of glycosylation. Affiliated tissues include spinal cord and eye, and related phenotypes are hyperreflexia and abnormal pyramidal sign