Sandhoff disease, also known as Jatzkewitz-Pilz syndrome and Hexosaminidase A and B deficiency, is a rare inherited disorder that progressively destroys nerve cells (neurons) in the brain and spinal cord.
The frequency of Sandhoff disease varies among populations. This condition appears to be more common in the Creole population of Northern Argentina; the Metis Indians in Saskatchewan, Canada; and people from Lebanon. The most common and severe form of Sandhoff disease becomes apparent in infancy. However, signs and symptoms can begin in childhood, adolescence, or adulthood and are usually milder than those seen with the infantile form.
Mutations in the HEXB gene cause Sandhoff disease. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Infants with this disorder typically appear normal until the age of 3 to 6 months, when their development slows and muscles used for movement weaken. Affected infants lose motor skills such as turning over, sitting, and crawling. They also develop an exaggerated startle reaction to loud noises. As the disease progresses, children with Sandhoff disease experience seizures, vision and hearing loss, intellectual disability, and paralysis. An eye abnormality called a cherry-red spot, which can be identified with an eye examination, is characteristic of this disorder. Some affected children also have enlarged organs (organomegaly) or bone abnormalities. Children with the severe infantile form of Sandhoff disease usually live only into early childhood.
Juvenile onset of the disease shows symptoms starting at age 3 ranging to age 10 and although the child usually dies by the time they are 15, it is possible for them to live longer if they are under constant care.
Adult onset of the disease is classified by its occurrence in older individuals and has an effect on the motor function of these individuals. It is not yet known if Sandhoff Disease will cause these individuals to have a decrease in their life span.
Characteristic features of late-onset forms of Sandhoff disease include:
- Muscle weakness
- Loss of muscle coordination (ataxia)
- Other problems with movement
- Speech problems
- Mental illness
Currently Sandhoff disease does not have a cure. To reduce some symptoms that may occur with Sandhoff disease, the patient may take anticonvulsants to manage seizures or medications to treat respiratory infections. They must consume a precise diet consisting of puree foods due to difficulties swallowing. Constant surveillance is required because they can suffer from aspiration or lack the ability to change from the passage way to their lungs versus their stomach and their spit travels to the lungs causing bronchopneumonia. The patient also lacks the ability to cough and therefore must undergo a treatment to shake up their body to remove the mucus from the lining of their lungs. Medication is also given to patients to lessen their symptoms including seizures.