Sandhoff is a rare genetic disorder characterized by the gradual degeneration of nerve cells (neurons) in the brain and spinal cord. The most common and severe form of the disease may appear in infancy (a few months after birth).
Usually, infants with this disorder may appear normal until the age of 3 to 6 months, but after that their growth slows down and the muscles used for movement become weak. Apart from this, there is also a decrease in motor skills, due to which there may be difficulty in turning, sitting and walking.
Another hallmark of the disease is an abnormal appearance of the eye, known as a cherry-red spot. Some children may notice a condition like enlargement of their limbs or bones. In severe cases of the disease, infants usually do not survive beyond the age of two.
Symptoms of Sandhoff disease
Signs and symptoms of this disease may include –
- Having trouble eating
- Weakness ( lethargy )
- Red spots can usually be seen in the eyes.
Other symptoms may include a decrease in the development of fine motor and gross motor abilities. Fine motor refers to the ability to pick up and hold small objects, while gross motor includes movements that are performed by larger muscles such as the arms and legs.
Apart from this, there may be a persistent decrease in mental health, due to which problems such as muscle weakness, retardation, seizures, blindness or abnormally enlarged spleen can be seen.
Causes of Sandhoff’s disease
Sandhoff disease is an ARG disorder, which means that an affected person has the defective gene passed down from his or her parents. The disease is caused by a mutation in a gene called HEXB. The HEXB gene provides instructions for making a protein that is part of beta-hexosaminidase A and beta-hexosaminidase B, two important enzymes in the nervous system.
If the HEXB gene is defective, the functions of enzymes called beta-hexosaminidase A and beta-hexosaminidase B can be disrupted. These enzymes are located in the lysosome. Lysosomes are cell organelles that contain digestive enzymes. Inside the lysosome, these enzymes break down fatty substances and other harmful molecules. Specifically, beta-hexosaminidase A helps break down a fatty substance called GM2 ganglioside.
Diagnosis of Sandhoff disease
Sandhoff disease can be diagnosed by examining the functions of an enzyme called HEXB to determine the activity of the enzymes hexosaminidase A and B. In affected individuals, both enzymes will either be absent or have very little ability to function. This disease can be easily diagnosed if either of the conditions is there.
Sandhoff disease treatment
There is no specific treatment for Sandhoff’s disease, but supportive treatment includes proper nutrition, hydration, and precautions such as keeping the airway open. Doctors believe that anti-epileptic drugs can be beneficial in curing the problem of seizures.
As the disease progresses, children with Sandhoff disease may have seizures , loss of vision and hearing, loss of intellectual ability (delay in learning new skills or delayed mental development), and Paralysis-like illness can be experienced. In such a situation, after noticing problems related to muscles, immediately tell your doctor, so that the available treatment options can be used as soon as possible.