Lysosomal Storage Disease

Definition

Lysosomal storage disease is a rare genetic disease. People who have it lack certain chemicals called enzymes or the enzymes do not work well. These chemicals help to break down substances in the body. Without them, toxic substances build up in the body and damage the cells and organs.

There are more than 50 types of lysosomal diseases. They are grouped based on which enzyme is lacking. .. Some examples of the types 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 faulty gene. The faulty gene affects the production of the enzymes. . The faulty gene must be passed byboth parents in order for the child to have it..

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 vary based on the type of the type of lysosomal storage disease and the cells or organs affected. Symptoms can appear shortly after birth or may be found later in life. They may be mild or severe. Some common problems may be:

• Joint stiffness and pain
• Easy bleeding and bruising
• Swollen belly
• Developmental delay that gets worse
• Problems with:
  • Hearing or sight
  • Behavior
  • Learning
  • Slow growth
  • Movement, weakness, or muscle spasms
  • Breathing, swallowing, or feeding
• Seizures
• Frequent infections

Problems can develop with major parts of the body, such as the:

• Nervous system
• Heart and blood vessels
• Lungs
• Digestive system
• Muscles and bones
• Blood
• Eyes

Diagnosis

Lysosomal storage disease may be found before or after a child is born. Tests to diagnose the disease may be:

Genetic testing before birth with:

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

After birth:

• The doctor will ask about the child's symptoms and past health . A physical exam will be done.
• Blood, urine (pee), and tissue testing will be done—to look for the specific enzyme that is causing the problem.

Treatment

There is no cure for lysosomal storage disease . Treatment is based on the type of the disease, the symptoms, and affected tissues or organs.. Options may include :

• Enzyme replacement therapy (ERT)—working enzymes are given through an IV.
• Stem cell transplant—stem cells are given to help the body make the missing enzyme. The stem cells come from donors or umbilical cord blood.
• Substrate reduction therapy (SRT)—medicine is givento reduce the toxins that build up in the cells .

Medicine, therapy, or other treatment may be needed to help manage other symptoms caused by these disorders.

Prevention

There are no current methods to prevent lysosomal storage disease.