Niemann-Pick Disease, Type C

Gene : NPC1

What is Niemann-Pick Disease Type C?

Niemann-Pick disease type C (NPC) is an inherited disorder where the body cannot break down lipids (fats) and cholesterol properly within their cells. As a result, cholesterol builds up in their spleen and liver and extra lipids are found in the brain. This build-up reduces spleen and liver function and can cause them to be abnormally large, sometimes leading to severe liver disease. Additional symptoms of NPC include breathing difficulties, developmental delay, seizures, lack of muscle tone, lack of coordination, and the inability of the individual with NPC to move their eyes up and down. Typically these symptoms appear between 4 and 10 years of age, but can appear in infancy or later on in adulthood. Currently there is no cure for NPC, although medical surveillance and care may help to improve some symptoms and overall condition of life. The majority of patients will pass away before they are 20 years old. One of the causes of NPC is pathogenic variants in the NPC1 gene.

How is Niemann Pick Disease Type C inherited?

NPC is inherited in an autosomal recessive manner. This type of inheritance requires the presence of two copies of a pathogenic variant in the gene for a person to have the genetic disease. Both parents must be carriers of a pathogenic variant in the gene in order to be at risk to have an affected child. The child must inherit a pathogenic variant from each carrier parent in order to be affected. There is a 1 in 4 chance that a baby will inherit two mutated copies of the gene and be affected when both parents are carriers.

What does it mean to be a carrier?

There are generally no signs or symptoms associated with being a carrier for NPC. However, the risk to have a child affected with NPC is increased. Testing of reproductive partners is recommended for carriers of NPC.

How common is Niemann Pick Disease Type C?

NPC is estimated to occur in 1 in 150,000 newborns, but it is more common in people of French-Candian descent in Nova Scotia, Canada.

Family References and Resources
Clinician References
What is Analyzed?
  • Full gene sequencing
Affected Systems





Carrier Rates
Detection Rate
Carrier Frequency
General Population > 88% 1 in 194

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