Niemann-Pick Disease, Type a, also known as niemann-pick disease, intermediate, protracted neurovisceral, is related to niemann-pick disease, type b and niemann-pick disease, and has symptoms including constipation, vomiting and muscle weakness. An important gene associated with Niemann-Pick Disease, Type a is SMPD1 (Sphingomyelin Phosphodiesterase 1), and among its related pathways/superpathways are Neuroscience and Sphingolipid metabolism. The drugs Miglustat and Glycoside Hydrolase Inhibitors have been mentioned in the context of this disorder. Affiliated tissues include bone marrow and liver, and related phenotypes are failure to thrive and developmental regression