The urinary glycosaminoglycans (uGAG) in eight patients (four adults and four children) with mastocytosis and eleven healthy subjects (five adults and six children) were examined for evidence of heparin and chondroitin sulfate E. The excretion of uGAG to urinary creatinine (uCr) in these patients was found to be 10.36 micrograms/mg for the children and 0.98 micrograms/mg for the adults, neither significantly different from healthy controls (p greater than 0.2). The uGAG was found to have a molecular mass between 10 kDa and 60 kDa by high performance liquid chromatography (HPLC). The content of the uGAG was found to consist of chondroitin sulfates without any evidence of heparin as assessed by specific chondroitinase ABC susceptibility. Disaccharide analysis following chondroitinase ABC digestion by HPLC Partisil-10 Pac separation revealed no evidence of chondroitin sulfate E and no differences in relative distribution of 0-, 4-, and 6-sulfated disaccharides between patients and healthy controls.