Niemann-Pick is inherited from your family and consists of a group of metabolic disorders in which lipids, fatty substances in your body, collect in the brain, spleen and liver cells. The diseases is triggered by the lack of an enzyme in lysosomes that is responsible for metabolizing the lipid called sphingomyelin.
There are 4 forms of the disease: Type A, Type B, Type C, and Type D. Sometimes they are referred to as type I (Types A and B) and type II (Types C and D). Different organs are affected, depending on what type of the disease the person suffers from. It can affect the respiratory system and the nervous system and each type presents different symptoms. Niemann-Picks disease is caused by a genetic mutation and can occur at any lifetime stage.
The symptoms of Niemann-Pick disease depend on the type of the disease. Some people only have a few symptoms and they are similar to the symptoms of other conditions.
Type A of Niemann-Pick disease tends to happen early on in the lifespan. Some of the signs of Type A are the loss of early motor skills that gets worse as time progresses, a cherry red spot on the eye, difficulties eating, and swelling of the abdominal area.
Type B symptoms do not usually occur until later in childhood and as late as the teen years. Younger children may still have abdominal swelling but the brain and nervous system are not usually involved. The symptoms are milder than Type A and can include respiratory infections that come back over and over again.
Type C of Niemann-Pick disease is most common in children that are school aged but it can also occur in early infancy and even in adulthood. The symptoms are an enlarged spleen and liver, jaundice (if infancy), seizures, difficulty moving limbs, and learning problems and intellectual decline. There can also be a loss of muscle tone and tremors and walking problems. Slurred speech and difficulty in moving the eyes up and down are also signs.
The symptoms of type D are very similar to those of type C.
Niemann-Pick disease is caused by mutations in specific genes. The genes in question determine how the body metabolizes fat, cholesterol, and lipids, and the mutation to those genes are inherited from mother to child. The genetic transmission of the defect is known as autosomal recessive inheritance, meaning both father and mother must have the defect in order for the child to develop Niemann-Pick disease.
There are three types of Niemann-Pick disease, though types A and B are similar in many ways. For one, both types are missing an enzyme called sphingomyelinase. In some cases, the enzyme may be present, but it may be malfunctioning. Either way, the resulting fat build-up is the same and it’s this process that causes cell dysfunction and can ultimately lead to cell death. Type A occurs in infants, while Type B mainly occurs in older children. While Type A is usually fatal, those with Type A Niemann-Pick disease very often survive into adulthood.
Type C is a rare form of Niemann-Pick disease and is inherited. When this condition develops, it affects the liver, spleen, or lungs and most often affects the brain.
The type of treatment that is recommended depends of the type of Niemann-Pick disease that you have. Unfortunately, there is not effective treatment at this time for type A and type D. Patients with type B have had good results with bone marrow transplants. Enzyme replacement and gene therapy are also being studied for treatment of type B. Miglustat is a medicine that is used to treat the symptoms of the nervous system that are common for type C. Other medicines may be prescribed to address other symptoms like seizures or loss of muscle tone.
While there’s no way to prevent Niemann-Pick disease at this time, genetic testing can help couples determine the likelihood of passing the condition on to a child. Even if neither parent has developed the disease, they may still carry mutated forms of the NPC1, NPC2, or SMPD1 genes. Following testing, couples should meet with a genetic therapist, someone specially trained to examine the test results and determine the likelihood of conceiving a child with Niemann-Pick disease.
Patients diagnosed with Niemann-Pick disease should see their doctor regularly to monitor the condition. Current and future treatments may help reduce the risk of developing complications caused by the condition. A doctor may also be able to help reduce the symptoms.