PThalassemia Phenotype With Normal pGlobin Gene Sequences

A limited proportion of individuals with the p-thalasse-mia carrier phenotype show completely normal p-globin gene sequences as well as normal LCR sequences. Recently, mutations in the general transcription factor TFIIH coding for a specific helicase have also been shown to be associated with p-thalassemia carrier phenotype besides tricothiodystrophy. Furthermore, depending on the site of mutation, mutations in GATA-1 resulted either in dyserythropoietic anemia and thrombocytopenia or thrombocytopenia and p-thalasse-mia carrier phenotype. The results indicate that the p-thalassemia carrier phenotype may result from mutation in a transcription factor regulating the function of the p-globin gene.

1. Heterozygosity for mutations in the p-globin gene that result in hyperunstable hemoglobins (dominant p-thalassemia), which precipitates in the red cell membrane together with unassembled a-globin chains, resulting in markedly ineffective erythropoiesis. Most of these p-globin gene mutations lie in the third exon and lead to the production of a markedly unstable Hb variant often not detectable in peripheral blood. Up to now, 32 dominant p-thalassemias have been described; all of them, but one, i.e., Cd121 G! T described in

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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