Ultrastructural study of the vacuoles in the peripheral lymphocytes in juvenile amaurotic idiocy. Juvenile form of generalized ceroid lipofuscinosis.

Lymphocytes of the peripheral blood of 31 patients with juvenile amaurotic idiocy (juvenile form of ceroid lipofuscinosis) were examined with the electron microscope. In all cases, intracytoplasmic clear vacuoles were present, containing round hollow, fingerprint and highly electron dense structures. The combination of these structures, not necessarily in one and the same vacuole, was considered to be highly indicative for the diagnosis of juvenile amaurotic idiocy. In addition to these three structures, parallel tubular inclusion bodies, rectilinear profiles and rod-shaped structures were found but in a number of the cases. The parallel tubular inclusion bodies were not regarded as having any diagnostic significance.