Gangliosidosis is a rare genetic disease characterized by the decrease or absence of the activity of the beta-galactosidase enzyme, which is responsible for the degradation of complex molecules, leading to their accumulation in the brain and other organs.
This disease is especially serious when it appears in the first years of life and the diagnosis is made based on the symptoms and characteristics presented by the person, as well as the result of tests that show the activity of the enzyme beta-galactosidase and the presence of the mutation in the GBL1 gene, which is responsible for regulating the activity of this enzyme.
Main symptoms
The symptoms of gangliosidosis vary according to the age they appear, and the disease is considered milder when the symptoms appear between 20 and 30 years of age:
- Gangliosidosis type I or infantile: Symptoms appear before 6 months of age and are characterized by progressive dysfunction of the nervous system, progressive deafness and blindness, weakening of the muscles, sensitivity to noise, enlarged liver and spleen, intellectual disability, gross face and cardiac changes, for example. Due to the large number of symptoms that can be developed, this type of gangliosidosis is considered the most serious and life expectancy is 2 to 3 years; Gangliosidosis type II: This type of gangliosidosis can be classified as infantile-late, when symptoms appear between 1 and 3 years, or juvenile, when they appear between 3 and 10 years. The main symptoms of this type of gangliosidosis are delayed or regressed motor and cognitive development, atrophy of the brain and changes in vision. Gangliosidosis type II is considered to be of moderate severity and life expectancy varies between 5 and 10 years; Gangliosidosis type II or adult: Symptoms can appear from 10 years of age, although it is more common to appear between 20 and 30 years, and is characterized by involuntary stiffening of the muscles and changes in the bones of the spine, which can result in kyphosis or scoliosis, for example. This type of gangliosidosis is considered mild, however the severity of symptoms may vary according to the level of activity of the beta-galactosidase enzyme.
Gangliosidosis is an autosomal recessive genetic disease, that is, for the person to present the disease, it is necessary that their parents are at least carriers of the mutated gene. Thus, there is a 25% chance of the person being born with the mutation in the GBL1 gene and 50% of the person being a carrier of the gene.
How the diagnosis is made
The diagnosis of gangliosidosis is made by assessing the clinical characteristics presented by the person, such as gross face, enlarged liver and spleen, psychomotor delay and visual changes, for example, which are more frequent in appearing at the earliest stages of disease.
In addition, tests are carried out to help confirm the diagnosis, such as neurological images, blood count, in which the presence of lymphocytes with vacuoles is observed, urine test, in which the high concentration of oligosaccharides in the urine is identified, and genetic testing, which aims to identify the mutation responsible for the disease.
The diagnosis can also be made during pregnancy through genetic testing using the chorionic villus sample or amniotic fluid cells. If this test is positive, it is important that the family is guided about the symptoms that the child may develop throughout life. Understand how genetic testing is done.
Treatment of gangliosidosis
Due to the low frequency of this disease, so far there is no well-established treatment, with symptoms being controlled, such as adequate nutrition, growth monitoring, speech therapy and physiotherapy to stimulate movement and speech.
In addition, periodic eye exams and monitoring of the risk of infections and heart disease are performed.
