Electron microscopic examination of skin biopsy as a cost-effective tool in the diagnosis of lysosomal storage diseases.

In this report, we have summarized our 9-year experience of over 100 proven cases of lysosomal storage disease using electron microscopic evaluation of skin biopsies as a screening tool. The skin biopsy was very specific in establishing the diagnosis in only two disorders, namely neuronal ceroid lipofuscinosis and mucolipidosis IV. Although the biopsy was not diagnostic in other categories of storage diseases, it proved to be highly sensitive and provided valuable clues to direct further investigations on the basis of morphologic appearance of stored material and the cell type affected. Only in two cases of biochemically proven lysosomal storage disease was the morphologic diagnosis unable to be confirmed. We have compared the cost of screening for storage disorders using skin biopsy with the cost of performing multiple lysosomal enzyme assays. Our findings indicate that the skin biopsy, although more expensive than a single enzyme assay, provides an efficient, rapid, cost-effective tool to screen for more than 35 lysosomal storage disorders.