Prevention:

All types of Niemann-Pick are autosomal recessive. This means that both parents are carriers -- they each carry one copy of the abnormal gene without having any signs of the disease themselves.

When both parents are carriers, there is a 25% chance that their child will have the disease and a 50% chance that a child will be a carrier.

Carrier detection testing is only possible if the specific genetic defect is identified. The defects involved in Types A and B have been extensively studied, and DNA tests for these forms of Niemann-Pick are available.

Genetic defects have been identified in the DNA of many patients with Type C, so it may be possible to diagnose those who carry the abnormal gene.

A few centers offer tests to diagnose a baby still in the womb.