Growing evidence indicates that TNF-alpha is involved in the
pathogenesis of POAG in several ways, primarly by induction of retinal
ganglion cells apoptosis and therefore optic nerve degeneration. TNF-alpha
and POAG relationship has been studied at the genetic level with variable
results in different populations. The transcription rate and the release of
the TNF-alpha cytokine have been reported to be affected by
polymorphisms in the promoter of the TNF- alpha gene. Polymorphisms at
positions -238 and -308 are the most frequent studied. Another
polymorphism, at the position -863 in the promoter region, has been less
studied, but a homozygous AA allele appears protective in a Chinese
population. Our aim was to assess the potential association of -863C/A
TNF-alpha gene promoter polymorphisms with POAG in an Egyptian
group of subjects. Genotyping of the TNF-alpha (-863) polymorphism
was done for 228 POAG patients and 230 control subjects using the PCRbased,
Restriction Fragment Length Polymorphism (RFLP) assay. TNFalpha
(-863) A/A genotype was absent in both groups. There was no
significant difference between both groups as regards to TNF-α (-863) A
allele carriage (6.14 versus 10.43%; p = 0. 099)). Also the genotype TNF-α
(-863) C/C and the frequency of the tumor necrosis factor-alpha (-863) C
allele did not significantly differ between both groups (93.86 versus 89.57%;
p = 0. 099) and 96.93 versus 94.78%; p = 0. 107) respectively. Our data
indicated that the TNF-alpha (-863) a allele is not linked with primary open
angle glaucoma protection among Egyptian patients. |
