Abstract
The Sanfilippo syndrome is characterized by storage of heparitinsulfate (HS) and chodroitinsulfate (CH-B) in liver and spleen, excretion of large amounts of HS in urine, moderate skeletal involvement, and severe mental retardation. Cultivated skin fibroblasts from patients accumulate abnormal amounts of CH-B intracellularly. A defect in lysosmal degradation of mucopolysaccharides (MPS) is shown by intracellular incorportation of S35O4 into MPS and by the rate of disappearance of the label from prelabeled cells. The foulthy degradation can be normalized either by mixing the cells from the patient with normal fibroblasts or by addition of preincubated media-fraction (precipitated at 80% HH3SO4) collected from normal cell lines or cells from other types of mucopolysaccharidosis. It is concluded that individual cell lines can substitute each with specific factors they lack originally. In case of Sanfilippo cells the missing factor is not dialyzable and is heat-labile. Crosscorrection was not obtained by mixing cell lines from some patients: other cell lines, however, did mutually correct each other. Thus, two different types of the clinically identical Sanfilippo syndrome could be established. Cell lines of the same type do not substitute each other for the factor, but their MPS metablism is corrected by any other cell line, including the other Sanfilippo type. Affected members of the smae family show the same type, indicating the presence of true genetic variants. Equal distribution of the two types was found in a larger group of Sanfilippo patients. There is evidence that at least two differnt biochemical defects in MPS metabolism can cause the clinical picture of the Sanfilippo syndrome.
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Wiesmann, U., Neufeld, E. 1. Evidence for two different biochemical defects causing Sanfilippo syndrome. Pediatr Res 5, 83 (1971). https://doi.org/10.1203/00006450-197102000-00006
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DOI: https://doi.org/10.1203/00006450-197102000-00006