Definition

Lysosomal storage disease is a group of disorders that affect specific enzymes in a specific location in the cell. These enzymes normally break down items for reuse in the cells. If the enzymes are missing or do not work properly, then the items can build up and become toxic. This happens in an area of the cell called lysosomes. The buildup leads to damage of cells and organs in the body.

There are about 50 types of lysosomal diseases. Each is characterized by the specific enzymes involved. Examples are:

• Fabry disease—affects the kidney, heart, and skin
• Gaucher disease —affects the spleen and bones, and causes anemia
• Hurler syndrome—affects the spleen, liver, joints, and eyes; causes intellectual disability and deafness
• Batten disease—affects the brain and eyes
• Niemann-Pick disease —affects the spleen, liver, and lungs
• Pompe disease—affects the liver, heart, and muscle tissue
• Tay-Sachs disease —affects the brain

Causes

Lysosomal storage disease is caused by a genetic problem. The genes that plan the production of the enzymes is faulty. Both parents must pass the gene on to the child in order for the disease to develop.

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Risk Factors

Lysosomal storage disease is more common in families with:

• Ashkenazi Jewish, Finnish, Asian, or Dutch heritage
• A family history of the disease
• Parents who are related to each other

Symptoms

Symptoms can be severe and appear shortly after birth or they can be mild and found later in life. Symptoms will depend on the specific type of disease. Some common problems are:

• Joint stiffness and pain
• Easy bleeding and bruising
• Swollen belly
• Problems with hearing or sight
• Developmental delays
• Problems learning
• Behavioral problems
• Facial and bone abnormalities
• Problems breathing
• Seizures

Diagnosis

The disease may be found both before and after a child is born. Tests may be:

Genetic testing before birth:

• Amniocentesis may be done to test the fluid in the uterus.
• Chorionic villus sampling (CVS) may be done to test cells from the placenta.

After birth:

• You will be asked about your child's symptoms and health history. A physical exam will be done.
• Blood, urine, and tissue testing to look for the specific enzyme that is causing the problem

Treatment

There is no cure. The goal is to manage symptoms caused by the missing enzymes. Options are:

• Enzyme replacement therapy (ERT) to deliver working enzymes to replace the faulty ones
• Stem cell transplant to encourage the body to make the faulty enzyme
• Bone marrow transplantation to slow the disease
• Medicine, such as substrate synthesis inhibition therapy (SSI) to decrease the item that build up in the cells due to faulty enzymes

Prevention

There are no known methods to prevent this health problem.