Germ line genetic variants of human telomerase reverse transcriptase (hTERT) are known to predispose for various malignancies including glioma. A study investigated genetic variation of hTERT gene T/G (rs2736100) and hTERT G/A (rs2736098) with respect to glioma risk.
Confirmed 106 cases were tested against 210 cancer-freehealthy controls by Polymerase chain reaction-restriction fragment length polymorphism technique (RFLP) for genotyping.
Homozygous variant 'GG' genotype of rs2736100 frequency was >4-fold significantly different in cases versus controls (39.6% 17.2%; p<0.0001). Further, variant 'G' allele was found significantly associated with cases (0.5 versus 0.2 in controls; p<0.0001). Homozygous variant rs2736098 'AA' genotype (35.8% vs. 23.8%) and allele 'A' (0.49 vs. 0.34) showed a marked significant difference in cases and controls respectively (p<0.05). In hTERT rs2736100, GG genotype significantly presented more in higher grades and GBM (p<0.0001). Besides GG variant of hTERT rs2736100 had poor probability in overall survival of patients as compared to TG and TT genotype (log rank p=0.03). Interestingly, two haplotypes of hTERT rs2736100/rs2736098 were identified as GG and GA that conferred >3- and 5-fold risk to glioma patients respectively wherein variant G/A haplotype was observed to pronounce highest impact to confer glioma risk (p<0.0001).
The study indicates that hTERT rs2736098 and rs2736100 variants play an important role to confer a strong risk to develop glioma. Further, hTERT rs2736100 GG variant seem to play a role in bad prognosis of glioma patients. Haplotypes GG and GA could prove as vital tool to monitor the risk for glioma patients 1).