Niemann-Pick disease is a rare inherited degenerative nerve
disease caused by the deficiency of the enzyme called sphingomyelinase, which
leads to the buildup of a fatty substance (sphingomyelin) in cells in the
liver, spleen, lymph nodes, and bone marrow. Niemann-Pick disease is most
commonly seen in families of Eastern European (Ashkenazi) Jewish
At least five types of Niemann-Pick disease have been
identified. The most common are type A and type B.
- Type A usually causes symptoms by 6 months of
age. Symptoms may include feeding difficulty, vomiting, and abdominal
distention from an enlarged spleen and liver. Some babies have a cherry-red
spot in the membrane that lines the back of the eye (retina). Infections such
as pneumonia are common. Death usually occurs by the age of 4.
- Type B
disease is a milder form that does not affect the brain. Children are usually
diagnosed during early childhood because of enlargement of the liver or spleen.
Teenagers with type B disease may have frequent lung infections. Most people
with type B Niemann-Pick disease live into their 30s or 40s.
- Type C
usually shows up during childhood. It can cause breathing problems, liver
disease, developmental delays, seizures, low muscle tone, and feeding problems.
It is the rarest type of Niemann-Pick disease. Most people with type C die by
the age of 20. The kind of genetic change (mutation) determines whether a
person has type C1 or C2.
There is no treatment for Niemann-Pick disease. Support
groups and counseling can be helpful for people with Niemann-Pick disease and
for their families. Genetic testing is recommended to identify carriers of the
disease and help guide decisions about having children.