title: A case of ataxia telangiectasia with unbalanced glucose 6-phosphate dehydrogenase mosaicism in the granulocytic/monocytic lineages.
abstract: Ataxia telangiectasia is a genetically determined disease with multi-system abnormalities and a high incidence of neoplasia. In order to define the nature of the association between ataxia telangiectasia and malignancy, we investigated a patient with the disease and heterozygote for the Mediterranean variant of the X-linked marker glucose 6-phosphate dehydrogenase. Enzymatic mosaicism in hemopoietic and nonhemopoietic cells was evaluated with the 2-deoxy glucose 6-phosphate technique. While erythrocytes, platelets, and lymphocytes expressed the same double-enzyme phenotype as tissues of nonhemopoietic origin, granulocytes and monocytes expressed almost exclusively the Mediterranean-type enzyme. We suggest that, as the result of genetic instability at the hemopoietic stem-cell level, the granulocytic/monocytic progeny enjoyed a proliferative advantage and became the predominant clone.
mesh_terms: D001260:Ataxia Telangiectasia / Q000201:enzymology / Q000235:genetics*; D002648:Child; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics*; D006098:Granulocytes / Q000201:enzymology*; D006579:Heterozygote; D006801:Humans; D009000:Monocytes / Q000201:enzymology*; D009030:Mosaicism; D010375:Pedigree
chemical_list: D005954:Glucosephosphate Dehydrogenase