Galactitol and galactonate in red blood cells of children with the Duarte/galactosemia genotype.
We measured galactitol, galactonate, and galactose-1-phosphate in the red blood cell (RBC) to elucidate the biochemical phenotype of infants with a Duarte/galactosemia (D/G) genotype by isotope dilution GC/MS. The RBC galactonate, galactitol and Gal-1-P were quantified in 14 D/G newborns on a lactose containing formula or breast milk, eight D/G newborns on a galactose-free formula, and 18 D/G children between 1 and 2 years of age that were on a regular diet. The results were compared with those of non-galactosemic subjects of comparable age. In the D/G newborns on regular formula/breast milk, the levels of RBC galactitol, galactonate, and Gal-1-P were significantly higher than those of D/G newborns on diet treatment and non-galactosemic newborns. There was no difference in the levels of RBC galactitol, galactonate, and Gal-1-P between D/G newborns on a lactose-restricted diet and the control group. There appears to be two different responses to dietary galactose intake in D/G children. The first group of D/G children placed on a regular diet after a year of lactose restriction had higher RBC galactitol, galactonate levels than those of non-galactosemic children. The mean level of RBC galactonate was higher and the mean value of RBC galactitol was as high as that of galactosemic (G/G) patients on diet treatment. The second group of D/G children on a regular diet had normal levels of RBC galactitol and galactonate. The levels of RBC Gal-1-P were normal in both groups of D/G patients. The alternative pathway products may reflect galactose intake better than RBC Gal-1-P in D/G children.
Ficicioglu
Can
C
The Section of Biochemical Genetics and the Metabolic Research Laboratory, The Children's Hospital of Philadelphia, The Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
Yager
Claire
C
Segal
Stanton
S
D004912:Erythrocytes / Q000378:metabolism*; D004376:Galactitol / Q000097:blood*; D005693:Galactosemias / Q000235:genetics*; D008401:Gas Chromatography-Mass Spectrometry; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D013400:Sugar Acids / Q000097:blood*
D013400:Sugar Acids; D004376:Galactitol; C012991:galactonic acid