الفهرس 
ThalassemiaOnly 14 pages are availabe for public view
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Abstract
Clinical severity of β-thalassaemia depends on the types of β-gene mutations
involved. It can also be influenced by genetic factors like concomittant α-
thalassaemia and increased γ-chain production. Several loci are implicated in
higher production of HbF. The Xmn I restriction site at -158 position of the Gγ-
gene is associated with increased expression of the Gγ-globin gene and higher
production of HbF .This study aims to determine the frequency of the Gγ Xmn I
polymorphism in β-thalassaemia patients in Egypt and its corelation to the HBF
Level and clinical severity of the disease. we investigated the Xmn I
polymorphism in 100 children with β-thalassaemia major using polymerase
chain reaction (PCR-RFLP)-restriction fragment length polymorphism. we
found that ninety four children had XmnI (-/-)genotype (94%) and six children
had XmnI (+/-) genotype. On the other hand the study found that the presence
of this polymorphism influences Hb F concentration and ameliorate the clinical
severity of the disease .