Can you tell me how to know if you are a carrier of niemann-pick disease?

See a geneticist: Niemannn-pick disease is autosomal recessive. Thus, both parents would have to be carriers for the child to manifest the disease. Niemann-pick is divided into types a, b, c, d. For types a and b there are dna tests that may be done to detect if one is a carrier. If this is something you are concerned about, a physician that specializes in genetics may be able to direct you to the exact test.