Submitted August 22, 2006
Accepted November 9, 2006
Molecular basis of glutathione reductase deficiency in human blood cells
Nanne M Kamerbeek, Rob van Zwieten, Martin de Boer, Gert Morren, Herma Vuil, Natalja Bannink, Carsten Lincke, Koert M Dolman, Katja Becker, R Heiner Schirmer, Stephan Gromer, and Dirk Roos*
Sanquin Research & Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
Dept of Pediatrics, Erasmus Medical Center, Location Sophia, Rotterdam, Netherlands
Pediatric Department, Medical Center Rijnmond-Zuid, Location Clara, Rotterdam, Netherlands
Emma Childrens Hospital, Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
Biochemie-Sentrum Heidelberg, Heidelberg University, Heidelberg, Germany
* Corresponding author; email: d.roos{at}sanquin.nl.
Hereditary glutathione reductase (GR) deficiency was found in only two cases when testing more than 15,000 blood samples. We have investigated the blood cells of two patients (1a and 1b) in a previously described family suffering from favism and cataract and of a novel patient (2) presenting with severe neonatal jaundice. Red blood cells and leukocytes of the patients in family 1 did not contain any GR activity, and the GR protein was undetectable by Western blotting. Owing to a 2246-bp deletion in the patients' DNA, translated GR is expected to lack almost the complete dimerization domain, which results in unstable and inactive enzyme. The red blood cells from patient 2 did not exhibit GR activity either, but the patient's leukocytes contained some residual activity that correlated with a weak protein expression. Patient 2 was found to be a compound heterozygote, with a premature stop codon on one allele and a substitution of glycine330, a highly conserved residue in the superfamily of NAD(P)H-dependent disulfide reductases, into alanine on the other allele. Studies on recombinant GR G330
A revealed a drastically impaired thermostability of the protein. This is the first identification of mutations in the GR gene causing clinical GR deficiency.
