What is Gangliosidosis GM1 Type II?
GM1 gangliosidosis type II (juvenile systemic lipidosis, Derry disease) differs phenotypically from GM1 gangliosidosis type I usually with a late onset (after the first year of life), slow progression, minimal bone damage and lack of damage to internal organs.
Causes of Gangliosidosis GM1 Type II
A little more than 20 cases of the disease have been described. As a result of b-galactosidase deficiency, the level of accumulation of GM1-gangliosides in the gray matter of the brain is 10 times higher than normal.
Symptoms of Gangliosidosis GM1 Type II
During the first year of life the child develops normally. By the end of the first year, ataxia and dysarthria appear, convergent squint, muscular hypotonia, which spastic tetraparesis soon replace. There is a rapid regression of acquired skills, lost interest in the environment, develop lethargy, convulsive syndrome, difficult to treat.
The life expectancy of patients with GM1-gangliosidosis type II is from 3 to 10 years. Patients die from recurrent bronchopulmonary infections.
Diagnosis of Gangliosidosis GM1 Type II
The diagnosis is made on the basis of determining the activity of beta-galactosidase. The differential diagnosis must be carried out with metachromatic leukodystrophy and youthful GM2-gangliosidosis, it is based on the determination of the activity of specific enzymes.