Diagnosis of Niemann-Pick disease begins with a thorough physical exam, including a detailed medical history, discussion of symptoms and family history. Niemann-Pick disease is rare and its symptoms can be confused with other diseases. Diagnostic techniques depend on the type of Niemann-Pick disease.
- Type A or B. Using a blood sample or a bone marrow sample (biopsy), experts measure how much acid sphingomyelinase (ASM) is in white blood cells to confirm the diagnosis.
- Type C. Experts take a small sample of skin to test for Niemann-Pick to assess how the cells move and store cholesterol. DNA testing for NPC1 and NPC2 genes can be done using a blood sample.
Other tests may also be done, such as:
- Magnetic resonance imaging (MRI). An MRI of the brain may show loss of brain cells. However, in the early stages of Niemann-Pick, an MRI may be normal because symptoms typically occur before the loss of brain cells.
- Eye exam. An eye exam can show symptoms that may be an indication of Niemann-Pick disease, such as eye movement difficulties.
- Genetic testing. Genetic testing may show the genetic mutations that cause Niemann-Pick types A, B and C disease. DNA tests can show who the carriers are for all types of Niemann-Pick disease if the mutations have been described in the first person identified in a family (the index case).
Read more about skin biopsy, bone marrow biopsy, MRI and genetic testing.