Diagnosis

Diagnosis of Niemann-Pick disease begins with a thorough physical exam, which can show an early warning sign such as an enlarged liver or spleen. Your doctor will also take a detailed medical history and discuss symptoms and family health 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 or skin sample (biopsy), experts measure how much sphingomyelinase 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.

Other tests also may be done, such as:

• Magnetic resonance imaging (MRI). An MRI of the brain may show loss of brain cells. But 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 signs that may be an indication of Niemann-Pick disease, such as eye movement difficulties.
• Genetic testing. DNA testing of a blood sample may show the specific abnormal genes that cause Niemann-Pick types A, B and C. 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).
• Prenatal testing. Ultrasound can detect the enlarged liver and spleen that's caused by type C. And amniocentesis or chorionic villus sampling may be used to confirm a diagnosis of Niemann-Pick.