sphingomyelinase

noun

sphin·​go·​my·​elin·​ase -ˈmī-ə-lə-ˌnās, -ˌnāz 

: any of several enzymes that catalyze the hydrolysis of sphingomyelin and are lacking in some metabolic deficiency diseases (as Niemann-Pick disease) in which sphingomyelin accumulates in bodily organs (as the spleen and liver)