Galactosialidosis. Late infantile type. Combined alpha-neuraminidase and beta-galactosidase deficiency.
Incidence
Autosomal recessive disease. Similar phenotype than Sialidosis II late infantile (chronic) form.
Clinical Characteristics
In some patients, the disease appears in the first years of life. Motor development is generally delayed. Most children walk late with an unsteady gait and are clumsy. Mental retardation rapidly becomes evident. Seizures and myoclonus are often added. Characteristic facial features consist of mild gargoil-like (Hurler-like) appearance. Short stature, clinical and radiological evidence of dysostosis multiplex and macular cherry red spots. Punctuate lens opacities may also be seen. Hepatosplenomegaly is observed and often there are angiokeratomas. Some children have been troubled by hernias and recurrent respiratory infections during the first months of life. Renal failure with proteinuria is a possible threat. The course of the disease is relatively rapid and most children do not survive the late childhood or early adolescence. Thin layer chromatography of the urine demonstrates high concentration of sialylated oligosaccharides several hundred times greater than normal. Under the electron microscope, clear membrane-bound inclusions are found in biopsies of skin fibroblasts, liver and in bone marrow histiocytes. There is marked deficiency of the activity of alpha-neuraminidase and beta-galactosidase in cultured fibroblasts and leukocytes. Clear vacuoles containing various granular inclusion are found in most organs including liver, spleen, lymph nodes and cerebral neurons.
Precipitants
no
Provocation Tests
no
Diagnostic Procedures
EB-W, EB-F. There is excretion of sialylated oligosaccharides in urine and a marked deficiency of the activity of alpha-neuraminidase and beta-galactosidase.