An inherited metabolic disorder in which harmful amounts of lipids accumulate in cells and tissues. Because of a functionally impaired hydrolase or auxiliary protein, their lipid substrates cannot be degraded, accumulate in the lysosome, and slowly spread to other intracellular membranes. [ http://www.ncbi.nlm.nih.gov/pubmed/21502308 http://en.wikipedia.org/wiki/Lipid_storage_disorder ]