A ganglioside biosynthesis disorder caused by (N-acetylneuraminyl)-galactosylglucosylceramide N-acetyl transferase (E.C. 2.4.192) deficiency with excessive accumulation of ganglioside GM3 in the liver and brain tissue and absence of higher ganglioside homologs. Clinical features include limpness, retarded psychomotor development, coarsening of facial features, macroglossia, gingival hypertrophy, hepatosplenomegaly, inguinal hernia, and stubby hands and feet. Most patients die in infancy.
