title: Endogenous galactose formation in galactose-1-phosphate uridyltransferase deficiency.
abstract: Patients with classical galactosaemia (galactose-1-phosphate uridyltransferase (GALT) deficiency) manifest clinical complications despite strict dietary galactose restriction. Therefore the significance of endogenous galactose production has been assessed. Previous in vivo studies primarily focused on patients homozygous for the most common genetic variant Q188R but little is known about other genetic variants. In the present study the endogenous galactose release in a group of non-Q188R homozygous galactosaemic patients (n = 17; 4-34 years) exhibiting comparably low residual GALT activity in red blood cells was investigated. Primed continuous infusion studies with D-[1-(13)C]galactose as substrate were conducted under post-absorptive conditions and in good metabolic control. The results demonstrate that all patients exhibiting residual GALT activity of <1.5% of control showed a comparable pathological pattern of increased endogenous galactose release irrespective of the underlying genetic variations. Possible implications of the findings towards a more differentiated dietary regimen in galactosaemia are discussed.
authors.affiliation: Institute of Clinical Biochemistry and Pathobiochemistry, German Diabetes Center at the Heinrich-Heine-University Duesseldorf, Leibniz Center for Diabetes Research , Duesseldorf , Germany and.
authors.forename: Peter
authors.initials: P
authors.lastname: Schadewaldt
authors.forename: Loganathan
authors.initials: L
authors.lastname: Kamalanathan
authors.forename: Hans-Werner
authors.initials: HW
authors.lastname: Hammen
authors.forename: Jorg
authors.initials: J
authors.lastname: Kotzka
authors.forename: Udo
authors.initials: U
authors.lastname: Wendel
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D005690:Galactose / Q000096:biosynthesis* / Q000378:metabolism; D005693:Galactosemias / Q000097:blood / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D008297:Male; D005694:UTP-Hexose-1-Phosphate Uridylyltransferase / Q000172:deficiency*; D055815:Young Adult
chemical_list: D005694:UTP-Hexose-1-Phosphate Uridylyltransferase; D005690:Galactose
keywords: Carbon isotopes; galactitol; galactonic acid; galactosaemia; galactose; galactose-1-phosphate uridyltransferase; human; metabolism