KEY FACTS OF SANDHOFF

Sandhoff disease is a lysosomal genetic, lipid storage disorder caused by the inherited deficiency to create functional beta-hexosaminidases A (Hex-A) and beta-hexosaminidases B (Hex-B).

INCIDENCE

Sandhoff affects 1 in 300,000 people.

CHILDREN

Affected babies die in early childhood.

NO TREATMENT

There is no treatment for Sandhoff.

WHAT CAUSES SANDHOFF

Mutations in the HEXB gene causes Sandhoff disease. The gene provides instructions for making a protein crucial to the enzymes Hex-A and Hex-B which function in nerve cells to break down fatty substances, complex sugars, and molecules that are linked to sugars. In particular, Hex-A breaks down a fatty compound called GM2 ganglioside. Mutations in the HEXB gene disrupt the activity of these enzymes, preventing the breakdown of GM2 and other molecules. As a result, progressive damage caused by the resulting buildup of GM2 leads to the destruction of nerve cells.

A SIMILAR DISEASE

As a rare autosomal recessive neurodegenerative disorder, Sandhoff is clinically almost indistinguishable from Tay–Sachs disease. There are three subsets of Sandhoff disease based on when first symptoms appear: classic infantile, juvenile and adult late onset.

HEXB

The defected gene that causes Sandhoff.

HEXOSAMINIDASE A

One of the enzymes reduced / missing in Sandhoff patients.

HEXOSAMINIDASE B

One of the enzymes reduced / missing in Sandhoff patients.

SYMPTOMS OF SANDHOFF

Sandhoff disease symptoms are clinically very similar to Tay-Sachs. The classic infantile form of the disease has the most severe symptoms and is incredibly hard to diagnose at an early age. Adult and juvenile forms of Sandhoff disease are more rare then the infantile form and in these cases individuals suffer cognitive problems and a loss of muscle coordination that eventually destroys their ability to walk. As in Tay-Sachs, younger suffers of Sandhoff have a limited life expectancy as the disease progresses.

THE VARIANTS OF SANDHOFF

As a rare autosomal recessive neurodegenerative disorder, Sandhoff is clinically almost indistinguishable from Tay–Sachs disease, another genetic disorder that disrupts beta-hexosaminidases A and S. There are three subsets of Sandhoff disease based on when first symptoms appear: classic infantile, juvenile and adult late onset.

INFANTILE

The most common form of Sandhoff.

JUVENILE

This form presents in childhood.

ADULT ONSET

The rarest for of Sandhoff.

INHERITANCE

Autosomes are the non-sex-related chromosomes. The term autosomal recessive inheritance means that the effects of possessing a single copy of a disease-causing gene are hidden. With a recessive condition, a person may be a carrier of a disease gene, but may have no noticeable effect on their everyday health. A positive diagnosis of Sandhoff in an individual means that each parent is a carrier of a disease-causing mutation on the specific gene which causes the disease.

TREATING SANDHOFF

At the moment there is no cure for Tay-Sachs or its associated diseases. Children affected with Tay-Sachs have no hope unless we help raise funds to aid the research on the way. A cure for Tay-Sachs will also mean a cure for over 70 other Lysosomal Storage Diseases as well as other neurological conditions such as Parkinson’s, Alzheimer’s and Multiple-Sclerosis.