A Variant Form of Mucolipidosis IV: Report on 4 Patients From the Indian Subcontinent

The clinical manifestations and histopathologic and neuroimaging findings in 4 Indian patients with a variant form of mucolipidosis IV are described. The presenting symptoms were psychomotor delay, spastic paraplegia, and mild mental retardation. One patient also had visual deterioration due to optic atrophy. None had corneal or retinal abnormalities. Magnetic resonance imaging in 3 patients showed a uniformly thin corpus callosum in all patients and white matter changes in 2 patients. Electron microscopic examination of skin biopsy specimens revealed storage bodies characteristic of mucolipidosis IV These patients differ from previously described patients with this disorder in the absence of corneal abnormalities and in their presentation with spastic paraplegia during the second decade of life. Correct diagnosis is needed for genetic counseling, prognostication. and reduction of additional familial burden of this rare disease.