B variant GM2-gangliosidosis, also known as Sandhoff disease, is a rare genetic disorder that affects the metabolism of certain lipids in the body. Specifically, it is caused by a deficiency in the enzyme beta-hexosaminidase, which is responsible for breaking down a type of lipid called GM2 ganglioside.
As a result of this deficiency, GM2 ganglioside accumulates in the cells of the brain and nervous system, leading to progressive damage and dysfunction. Symptoms typically begin in infancy or early childhood and include developmental delays, muscle weakness, seizures, vision and hearing loss, and a cherry-red spot in the eye.
There are several types of GM2-gangliosidosis, including Tay-Sachs disease, which is a related disorder caused by a deficiency in a different enzyme involved in the metabolism of GM2 ganglioside. B variant GM2-gangliosidosis is a rarer form of the disease that typically has a more severe course.
There is currently no cure for B variant GM2-gangliosidosis, and treatment is primarily supportive, focusing on managing symptoms and improving quality of life. This may include medications to control seizures, physical and occupational therapy to maintain mobility and function, and communication and sensory aids to assist with hearing and vision loss.
Genetic counseling and testing may also be recommended for individuals with a family history of B variant GM2-gangliosidosis, as the disorder is inherited in an autosomal recessive manner.
