Type II Machado Joseph Disease (MJD), also known as Spinocerebellar Ataxia type 3 (SCA3), is a progressive neurodegenerative disorder characterized by movement problems, muscle wasting, and various neurological symptoms. It is a hereditary condition caused by a mutation in the ATXN3 gene, leading to the accumulation of toxic protein aggregates primarily in the brain and spinal cord.
Symptoms of Type II MJD typically manifest in early adulthood, between the ages of 10 and 50 years, and gradually worsen over time. Common signs include uncoordinated movements, tremors, muscle stiffness (spasticity), difficulty speaking or swallowing, and impaired balance and coordination. As the disease progresses, individuals may experience muscle weakness, respiratory problems, and even cognitive impairment.
Type II MJD is inherited in an autosomal dominant manner, meaning that a person only needs to inherit a mutated gene copy from one parent to develop the disease. However, the age of onset and severity can vary among affected individuals, even within the same family.
Currently, there is no cure for Type II MJD, and treatment mainly revolves around managing the symptoms and improving the quality of life. Physical therapy, speech therapy, and assistive devices can help maintain mobility and communication abilities. Medications may be prescribed to alleviate specific symptoms, such as muscle stiffness or depression. Genetic counseling is also recommended for affected individuals and their families to better understand the inheritance pattern and make informed decisions regarding family planning.
