Niemann-Pick Disease By Matt Demczko, MD, Mitochondrial Medicine, Children's Hospital of Philadelphia Reviewed / Revised Oct 2021 | Modified Sep 2022 View Patient Education Diagnosis Treatment More Information Niemann-Pick disease is a sphingolipidosis, an inherited disorder of metabolism, caused by deficient sphingomyelinase activity, resulting in accumulation of sphingomyelin (ceramide phosphorylcholine) in reticuloendothelial cells.