<prompt> Accumulation of sphingomyelin in phagocytic cells is feature ofGauchers diseaseNiemann pick dsTay sachs diseaseDowns syndrome  <response>: Ans. is b ie., Niemann pick disease First three options are types of Lysosomal storage disordersThe characteristic feature of lysosomal storage disorders is accumulation of specific macromolecules within cells that are normally metabolized by the cells. This is because of deficiency of one or other lysosomal enzymesSome important lysosomal storage disorders , the deficient enzymes and the stored macromolecule are listed below--Lysomal Storage DiseaseDeficient EnzymeStored Material Fabrys dsa- Galactosidase AGlobotriaosyl ceramide Gauchers dsAcid beta - glucosidaseGlucosyl-ceramidase Niemann - Pick dsSphingomyelinaseSphingomyelin Tay -Sachs dsb - hexosaminidase AGM2 gangliosides Sandhoff dsb - hexosaminidase A and BGM2 gangliosides Hurlers dsa - L-iduronidaseDermatan sulfate Heparan sulfate Hunters dsIduronate sulfataseDermatan sulfate Metachromatic leukodystrophyArylsulfatase -ACerebroside - sulfate Krabbes dsGalactosylceramidaseGalactosylceramide Galactosyl sphingosine 