The juvenile and chronic forms of GM ₂ gangliosidosis

Abstract

We report the cases of 5 patients from 2 sibships with the "adult" or chronic form of GM2 gangliosidosis and 2 patients from another sibship with the juvenile form. We demonstrated hexosaminidase A deficiency in all cases but in 1 sibship the enzymatic profile was identical to that in Tay-Sachs disease, whereas in the remaining 2 families it was that of the B1 variant. There was no correlation between the clinical features and the enzymatic profile. Hexosaminidase A deficiency should be considered in unexplained progressive neurologic disorders of childhood and adolescence, including isolated dementia. EMG evidence of anterior horn cell involvement in association with neurologic or cognitive deterioration may be a diagnostic clue in the juvenile forms.

The Natural History of Juvenile or Subacute GM2 Gangliosidosis: 21 New Cases and Literature Review of 134 Previously Reported

“…Clinical information about the symptoms at onset and its progression until the diagnosis was gathered retrospectively from parents through a detailed clinical protocol. * Refs 1,8,9,[11][12][13][14]18,20,22,. …”

“…7 Juvenile or subacute and the adult, also called late-onset or chronic, subtypes of this condition present later in childhood or in adulthood and progress more slowly. 1,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] The juvenile and adult forms of GM2 gangliosidosis differ from each other primarily by the impact of the disease on intelligence, which is minimal through much of the course of the adult or chronic variant.Several case reports and a small number of case series have been reported. 11,13,20,21 However, few studies have provided accurate descriptions of the natural clinical course of jGM2 in larger groups of patients.…”

“…1,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] The juvenile and adult forms of GM2 gangliosidosis differ from each other primarily by the impact of the disease on intelligence, which is minimal through much of the course of the adult or chronic variant.…”

“…The most common symptoms at onset were speech problems and developmental delay. Intellectual impairment, along with incoordination, † Refs 1,8,11,13,20,24,25,27,34,36,38,42,45,56,65,[68][69][70]74, and 91. ‡ Refs 1,20,25,27,29,34,38,42,56,74, and 91.…”

“…11,13,20,21 However, few studies have provided accurate descriptions of the natural clinical course of jGM2 in larger groups of patients. 21,23 We report here a series of 21 cases of juvenile or subacute GM2 gangliosidosis followed at 2 medical centers.…”