Human Genetics

, Volume 93, Issue 2, pp 167–169 | Cite as

On the molecular nature of the Duarte variant of galactose-1-phosphate uridyl transferase (GALT)

  • Hsien-Chin Lin
  • Lorne T. Kirby
  • Won G. Ng
  • Juergen K. V. Reichardt
Original Investigations


Galactosemia is an inborn error of galactose metabolism secondary to deficiency of galactose-1-phosphate uridyl transferase (GALT). GALT is a polymorphic enzyme and Duarte (D) is the most common enzyme variant. This variant is characterized by faster electrophoretic mobility and reduced activity. Duarte/galactosemia compound heterozygotes (D/G) are commonly identified in galactosemia newborn screening programs. However, these patients do not generally require treatment. By using a “candidate mutation” approach to define the molecular basis of the Duarte variant of GALT, a close association between the previously reported N314D polymorphism and the Duarte variant of GALT was found. We suggest that N314D encodes the D variant of GALT and that molecular testing for N314D might be useful to confirm a biochemical diagnosis of Duarte variant of GALT.


Galactose Screening Program Electrophoretic Mobility Newborn Screening Inborn Error 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Banroques J, Gregori C, Schapira F (1981) Purification and characterization of human erythrocyte uridylyl transferase. Biochim Biophys Acta 657:374–382Google Scholar
  2. Beutler E, Baluda MC (1966) Biochemical properties of human red cell galactose-1-phosphate uridyl transferase (UDP glucose: a D-galactose-1-phosphate uridyltransferase E. C. from normal and mutant subjects. J Lab Clin Med 67:947–954Google Scholar
  3. Flach JE, Reichardt JKV, Elsas LJ (1990) Sequence of a cDNA encoding human galactose-1-phosphate uridyl transferase. Mol Biol Med 7:365–369Google Scholar
  4. Kelley RI, Harris H, Mellman WJ (1983) Characterization of normal and abnormal variants of galactose-1-phosphate uridylyltransferase (EC by isoelectric focusing. Hum Genet 63:274–279Google Scholar
  5. Lee JES, Ng WG (1982) Semi-micro techniques for genotyping of galactokinase and galactose-1-phosphate uridyltransferase. Clin Chim Acta 124:351–356Google Scholar
  6. Leslie ND, Immerman EB, Flach JE, Florez M, Fridovich-Keil JL, Elsas LJ (1992) The human galactose-1-phosphate uridyl transferase gene. Genomics 14:474–480Google Scholar
  7. Mathai CK, Beutler E (1966) Electrophoretic variation of galactose-1-phosphate uridyltransferase. Science 154:1179–1180Google Scholar
  8. Ng WG, Bergren WR, Fields M, Donnell GN (1969) An improved electrophoretic procedure for galactose-1-phosphate uridyl transferase: demonstration of multiple activity bands with the Duarte variant. Biochem Biophys Res Commun 37:354–362Google Scholar
  9. Ng WG, Bergren WR, Donnell GN (1972) A new variant of galactose-1-phosphate uridyltransferase in man: the Los Angeles variant. Ann Hum Genet 37:1–8Google Scholar
  10. Reichardt JKV (1992) Genetic basis of galactosemia. Hum Mutat 1:190–196Google Scholar
  11. Reichardt JKV, Berg P (1988) Cloning and characterization of a cDNA encoding human galactose-1-phosphate uridyl transferase. Mol Biol Med 5:107–122Google Scholar
  12. Reichardt JKV, Woo SLC (1991) Molecular basis of galactosemia: mutations and polymorphisms in the gene encoding human galactose-1-phosphate uridylyltransferase. Proc Natl Acad Sci USA 88:2633–2637Google Scholar
  13. Segal S (1989) Disorders of galactose metabolism. In: Scriver CR, Beaudet AL, Sly WS, Valle D (eds) The metabolic basis of inherited disease, 6th edn. McGraw-Hill, New York, pp 453–480Google Scholar
  14. Shin YS, Niedermeier HP, Endres W, Schaub J, Weidinger S (1987) Agarose gel isoelectrofocusing of UDP-galactose pyrophosphorylase and galactose-1-phosphate uridyltransferase: developmental aspect of UDP-galactose pyrophosphorylase. Clin Chim Acta 166:27–35Google Scholar
  15. Williams VP, Helmer GR, Fried C (1982) Human galactose-1-phosphate uridylyltransferase: purification and comparison of the red blood cell and placental enzymes. Arch Biochem Biophys 216:503–511Google Scholar

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • Hsien-Chin Lin
    • 1
  • Lorne T. Kirby
    • 3
  • Won G. Ng
    • 4
  • Juergen K. V. Reichardt
    • 1
    • 2
  1. 1.Department of Biochemistry and Molecular BiologyUniversity of Southern California School of MedicineLos AngelesUSA
  2. 2.Institute for Genetic Medicine, University of Southern California School of MedicineLos AngelesUSA
  3. 3.Division of PathologyChildren's HospitalVancouverCanada
  4. 4.Division of Medical GeneticsChildrens' Hospital Los AngelesLos AngelesUSA

Personalised recommendations