Inheritance from both parents will result in the disease
Age range at onset:
Specialists you may see:
Three types occur. Significant white matter abnormalities only occur with type 1.
In type 1 symptoms appear at or soon after birth with poor feeding, lethargy, floppiness and sometimes swelling of the face and body. An abnormal facial appearance may be present. Development is very delayed and abnormal startle is common. Progressive physical and mental deterioration occurs and blindness is common.
Type 2 is slower in onset with first signs appearing between 6 months and 2 years with progressive motor and cognitive problems, abnormal startle and later onset of blindness. Life span averages between 3 and 10 years.
Type 3 usually starts between 10 and 20 years of age with abnormal walking and speech disturbance and the development of abnormal movements which are often slowly progressive.
Mutations in the GLB1 gene cause a reduction in the body’s ability to produce an enzyme called beta-galactosidase. This enzyme breaks down GM1 ganglioside. When this is not broken down, it builds up in nerve cells of the brain and spinal cord, causing the described symptoms.