This is also known as the storage disease as the result of various metabolic materials accumulating in the cells. This inherited lysosomal storage disorder over a period of time can affect the nerve cells of the brain and the spinal cord. There are three types of this disorder that are based on the age of onset and the symptoms that are evident. The classic infantile (type 1), juvenile (type 2) and adult onset or chronic (type 3) all vary in the features and the severity of the disorder. This condition is estimated to affect 1 in 100,000 to 200,000 infants.
Causes
This condition develops as the result of a mutation in the gene GLB1 which is important for the production of an enzyme known as beta-galactosidase. This helps with the breakdown of materials that are essential for the normal functioning of the brain’s nerve cells. As the result of the genetic mutation, the deficient in the functional enzymes, certain materials accumulate to a toxic level in various parts of the body, particularly in the brain. The affected individuals tend to have a milder form of this disorder when the higher activity of the beta-galactosidase enzyme is present than those with the lower activity of these enzymes. This condition is inherited in an autosomal recessive pattern meaning both the copies of the gene in each cell are defective.
Symptoms
The classic infantile (type 1) gangliosidosis, GM1 is the most severe type of this disorder that begins shortly after the birth of the infant. The symptoms include the developmental regression, seizures, enlargement of organs such as the liver and the spleen, coarse facial features, stiff joints, weak muscles, skeletal abnormalities and neurodegeneration. In addition, they may also have red spots in the eyes, blindness and the deafness can also occur by the time they complete one year age. The juvenile type can occur between the ages of 1 and 5 and includes dementia, problems with speech, ataxia and seizures. The adult onset may develop anywhere between the age of 3 and 30 with symptoms consisting of non-cancerous skin blemishes, corneal clouding and muscle atrophy.
Diagnosis
The diagnosis of this condition is done with the analysis of enzyme beta-galactosidase. Genetic testing is also possible in the identification of the mutation of the gene that is responsible for developing this disorder. The carrier-testing may be beneficial for the family members who can be at risk particularly if it is already prevalent in the family.
Treatment
This is a serious condition that can result in early death in most of the cases. There is no cure for this disorder or to prevent the progression of this condition. Although medications are available for the neurological symptoms that are evident, it does not affect the progression of the disease. However, some of the supportive treatment includes anticonvulsant medications for the seizures, proper nutrition and hydration.
References
https://rarediseases.info.nih.gov/diseases/10891/gm1-gangliosidosis
https://ghr.nlm.nih.gov/condition/gm1-gangliosidosis#inheritance
http://disorders.eyes.arizona.edu/handouts/gm1-gangliosidosis