Contributor: Gordon K. Klintworth
GM1-gangliosidosis type I (generalized gangliosidosis, pseudo-Hurler disease, Tay-Sachs disease with visceral involvement, infantile GM1-gangliosidosis, OMIM #230500) is one variant of GM1-gangliosidosis. It results from of an incomplete degradation of gangliosides because of mutations in the GLB1 gene that encodes acid-beta-glucosidase. Two other varieties of  GM1-gangliosidosis are recognized based to the age of onset [GM1-gangliosidosis type II and GM1-gangliosidosis type III], but they are both due to mutations in the smae gene. Generalized gangliosidosis manifests itself at birth or during infancy with a combination of neurological, ocular, and skeletal abnormalities. The phenotype of generalized gangliosidosis resembles Hurler syndrome in that affected individuals have coarse facial features, frontal bossing, depressed nasal ridge, hepatosplenomegaly, dysostosis multiplex, skeletal deformities, angiokeratomas, deterioration leads to death during the first decade.