Genetic heterogeneity of primary XXXX .

@entity1 @entity1522 @entity5859 @entity70686 @entity1307 @entity70687 @entity56 @entity74 @entity50652
@entity50652 ( @entity50652 ) is an @entity74 of erythroid progenitor cells resulting in elevated erythrocyte mass. Several mutations of the @entity5859 ( @entity5859 ) gene have been associated with @entity50652 , although in a few families the linkage between the @entity5859 gene and @entity50652 has been excluded. To examine the role of @entity5859 mutations in the pathogenesis of @entity50652 , we studied 43 unrelated @entity50652 subjects. Erythroid culture data were available in 26 subjects, and in all these subjects, we observed @entity56 of erythroid progenitors to @entity1307 (EPO). We screened all @entity5859 gene exons for mutations using ribonuclease cleavage assay and protein truncation test. We detected five mutations in exon VIII of the @entity5859 gene, four of which we reported earlier. A new @entity5859 gene mutation was found ( @entity70686 ) that changes codon 425 GAG to a termination codon, resulting in truncation of the @entity5859 by 84 @entity1522 . The @entity70686 mutation was found to segregate with the disease in the affected family and represents another example of a nonsense mutation associated with @entity50652 . We also report the first intronic mutation ( @entity70687 ) of the @entity5859 gene. The finding of only five disease-causing mutations in our @entity50652 @entity1 pool of 43 subjects (12%) indicates that @entity5859 gene mutations are not the major @entity74 associated with @entity50652 . The @entity56 of erythroid progenitors to EPO seen in all examined @entity50652 subjects suggests a dominant lesion of an as yet unidentified gene either at the level of the @entity5859 signaling pathway or another erythropoiesis regulating pathway.
