Manifestations and Classification

As mentioned in the preceding chapter, sialidosis seems to manifest itself in two principal phenotypes a severe form resembling a mucopolysaccharidosis, and a milder form with mainly neurological symptoms. 

Course slowly progressive death between 2-21 years of age progressive 

1 The mild and severe forms correspond to types 1 and 2 (infantile onset), respectively, of the classification of Lowden and O Brien (1979). 

In fact, all of the patients classified by Lowden and O Brien (1979) as sialidosis type 2, juvenile onset form, exhibited a p-galactosidase deficiency when it was looked for. 

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