GM1 Gangliosidosis
GM1 Gangliosidosis is a disorder of sphingolipid metabolism.
Sphingolipids are found throughout the body but play an
important role in the nervous system, including in myelin
sheaths and grey matter of the brain.
GM1 Gangliosidosis is an autosomal recessive disorder
caused by a deficiency in the enzyme Beta-galactosidase
encoded at chromosome 3p21.3. There are three types,
differentiated by symptoms. Type I consists of early hypotonia,
psychomotor retardation, and hepatosplenomegaly. Type II consists
of ataxia and changes in gait. Type III is highly variable and
can include a range of IQ from delayed to gifted; and occasionally
a cherry-red spot in the retina may be present. Infantile
presentation is within the first year of life, and the "adult
onset form" is diagnosed between 3 years and 30 years of life.
Currently, there is no effective medical cure for the underlying
disorder and symptoms are managed aggressively. Bone marrow
transplantation was successful in an individual with infantile/juvenile
GM1 gangliosidosis; however, no long-term benefit was reported.
Presymptomatic cord-blood hematopoietic stem-cell transplantation
has been advocated by some as a possible treatment because of
success in other lysosomal storage disorders.
