title: Galactitol and galactonate in red blood cells of galactosemic patients.
abstract: The red blood cell (RBC) concentration of galactitol and galactonate was measured in 27 patients with galactose-1-phosphate uridyltransferase (GALT) deficiency galactosemia and 19 non-galactosemic subjects by a newly devised isotope dilution gas chromatography/mass spectrometry (GC/MS) method. The method utilizing UL[13C]galactitol and UL[13C]galactonate was reproducible with excellent precision and recovery of 99%. The RBC galactitol in galactosemic patients on galactose-restricted diets averaged 5.98+/-1.2 microM (M+/-SD) with a range of 3.54-8.81 microM. The mean in non-galactosemic patients was 0.73+/-0.31 microM with a range of 0.29-1.29 microM. The mean of RBC galactonate in the same galactosemic patients was 4.16+/-1.32 microM (M+/-SD) with a range of 0.68-6.47, while the mean in non-galactosemic subjects was 1.94+/-0.96 (M+/-SD) with a range of 0.69-3.84. In galactosemic RBC the galactitol was higher than galactonate while this was reversed in non-galactosemic cells. RBC galactose-1-phosphate (Gal-1-P) measured at the same time as galactitol and galactonate was 30 times the level of the other two metabolites. There was no relationship between RBC Gal-1-P and galactitol or galactonate. The ability to measure all three galactose metabolites in the same procedure offers the possibility of augmented monitoring of the galactose metabolic status of patients. The measurement of RBC galactitol and galactonate presents a new means of characterizing galactosemic patients and their levels monitored over time may provide new insight in the development of long-term complications observed in afflicted patients.
authors.affiliation: Metabolic Research Laboratory, Department of Pediatrics, University of Pennsylvania, School of Medicine, The Children's Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA 19104-4399, USA.
authors.forename: Claire T
authors.initials: CT
authors.lastname: Yager
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Robert
authors.initials: R
authors.lastname: Reynolds
authors.forename: Stanton
authors.initials: S
authors.lastname: Segal
mesh_terms: D000293:Adolescent; D002138:Calibration; D002247:Carbon Isotopes; D002648:Child; D002675:Child, Preschool; D004912:Erythrocytes / Q000378:metabolism*; D004376:Galactitol / Q000097:blood*; D005693:Galactosemias / Q000097:blood*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D013400:Sugar Acids / Q000097:blood*
chemical_list: D002247:Carbon Isotopes; D013400:Sugar Acids; D004376:Galactitol; C012991:galactonic acid