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Niemann-Pick Disease


Matt Demczko

, MD, Mitochondrial Medicine, Children's Hospital of Philadelphia

Reviewed/Revised Dec 2021 | Modified Sep 2022

Niemann-Pick disease is type of lysosomal storage disorder Overview of Lysosomal Storage Disorders Lysosomal storage disorders are hereditary metabolic disorders. Hereditary disorders occur when parents pass the defective genes that cause these disorders on to their children. There are different... read more . Types A and B are sphingolipidoses and are caused by a buildup of sphingomyelin in the tissues. Type C is a lipidosis that is caused by a build up of cholesterol and other fats (lipids) in the cells. This disease causes many neurologic problems. Niemann-Pick disease occurs when parents pass the defective genes Genes Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body or the code for functional ribonucleic... read more Genes that cause this disease on to their children.

  • Niemann-Pick disease types A and B occur when the body lacks enzymes needed to break down sphingomyelin.

  • Niemann-Pick disease type C occurs when the body is not able to break down cholesterol and other lipids.

  • Symptoms vary by type but may include intellectual disability and neurologic problems.

  • The diagnosis is based on the results of prenatal screening tests, newborn screening tests (for types A and B), or biopsy of the liver.

  • Niemann-Pick disease cannot be cured.

Sphingolipidoses occur when people do not have the enzymes needed to break down (metabolize) sphingolipids, which are compounds that protect the cell surface and serve certain functions in the cells. There are many types of sphingolipidoses besides Niemann-Pick disease types A and B:

Types of Niemann-Pick disease

Niemann-Pick disease has several types. In types A and B, the deficiency of a specific enzyme called sphingomyelinase results in the accumulation of sphingomyelin (a product of fat metabolism). In type C, there is a defect in how fats (lipids) are moved around in a cell, resulting in accumulation of cholesterol and other fatty substances.

The most severe forms tend to occur in Ashkenazi Jewish people. The milder forms occur in all ethnic groups.

Children with type A (the most severe form) fail to grow normally and have several neurologic problems. These children usually die by age 2 or 3.

Children with type C develop symptoms during childhood, with seizures and neurologic deterioration. Type C is always fatal, and most children die before age 20.

Diagnosis of Niemann-Pick Disease

  • Prenatal screening tests

  • Newborn screening tests and/or biopsy of the liver

  • Blood and sometimes DNA tests

Doctors also measure levels of sphingomyelinase in white blood cells for types A and B. Genetic testing Genetic Counseling and Genetic Testing Before Pregnancy Genetic disorders are caused by abnormalities in one or more genes or chromosomes. Some genetic disorders are hereditary and others are spontaneous. Hereditary genetic disorders are passed down... read more , which is used to determine whether a couple is at increased risk of having a baby with a hereditary genetic disorder, is also available for all three types.

Tests of DNA (the building blocks of genes) may be done to identify carriers. Carriers Genetic Carrier Screening Genetic disorders are caused by abnormalities in one or more genes or chromosomes. Some genetic disorders are hereditary and others are spontaneous. Hereditary genetic disorders are passed down... read more are people who have an abnormal gene for a disorder but who do not have symptoms or visible evidence of the disorder.

Treatment of Niemann-Pick Disease

  • Possible bone marrow transplantation, stem cell transplantation, and enzyme replacement

None of the types of Niemann-Pick disease can be cured, and children tend to die of infection or progressive dysfunction of the central nervous system (the brain and spinal cord).

More Information

The following are English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

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