Reliability of the use of fructose 1-phosphate to detect Hunter cells in fibroblast-cultures of obligate carriers of the Hunter syndrome

Pulse-chase experiments measuring 35S-sulphate incorporation into acid mucopolysaccharides were performed in the presence and absence of fructose 1-phosphate on fibroblasts obtained from one skin-biopsy of 25 obligate Hunter carriers. The presence of fructose 1-phosphate significantly increased the accumulation of 35S-labelled acid mucopolysaccharides in fibroblast cultures of 23 obligate Hunter carriers. In one carrier, the accumulation of labelled acid mucopolysaccharides was significantly increased prior to the addition of fructose 1-phosphate, and in one of the 25 obligate carriers the 35S-sulphate incorporation was normal in the presence as well as in the absence of fructose 1-phosphate. Similar experiments performed on mixtures of Hunter cells and normal cells revealed that 20% Hunter cells should be present to obtain a significantly increased difference in between the incorporation in the presence and in the absence of fructose 1-phosphate. Fructose 1-phosphate had no effect on the accumulation of labelled mucopolysaccharides in fibroblast-cultures of seven women with no family history of mucopolysaccharidosis. The present results show that pulse-chase experiments measuring 35S-sulphate incorporation into fibroblasts, cultured in the presence of fructose 1-phosphate, can identify Hunter carriership, provided that the accumulation is normal prior to the addition of fructose 1-phosphate. Furthermore, 35S-sulphate incorporation in the absence of fructose 1-phosphate, higher than mean +4SD of normal control-fibroblasts indicates carriership.