ENDOTHELIAL NITRIC OXIDE SYNTHASE (ENOS) GENE POLYMORPHISM IS ASSOCIATED WITH AGE ONSET OF MENARCHE IN SICKLE CELL DISEASE FEMALES OF INDIA

ABSTRACT   Background and Objective :  Females with sickle cell disease (SCD) often show late onset of menarche. In transgenic sickle cell mouse, deficiency of gene encoding endothelial nitric oxide synthase (eNOS) has been reported to be associated with late onset of menarche. Thus to explore the possible association of eNOS gene polymorphism with age of onset of menarche in SCD females, 3 important eNOS gene polymorphism- eNOS 4a/b, eNOS 894G>T and eNOS-786 T>C  and  plasma nitrite levels were tested among three groups of females- SCD late menarche, SCD early menarche and control females. Methods : PCR-RFLP method for genotyping eNOS gene polymorphisms and quantification of plasma nitrite level by ELISA based commercial kits were used Results: SCD late menarche females showed significantly higher prevalence and higher association of heterozygous genotypes, higher frequency of mutant alleles ‘4a’, ‘T’ and ‘C’ as compared to that of control group and SCD early menarche group. The frequency of haplotype  ‘4a-G-C’ and haplotype’ 4b-G-C’ (alleles in order of  eNOS 4a/b, eNOS 894G>T and eNOS-786 T>C respectively) were found to be significantly high in SCD late menarche compared to combined groups of SCD early menarche and controls. SCD late menarche group had significantly low level of plasma nitrite concentration for all 3 eNOS gene polymorphisms as compared to controls and SCD early menarche females. Conclusion: eNOS gene polymorphism may influence age of onset of menarche in SCD females.   Key words : eNOS gene, sickle cell disease, menarche, haplotype, nitric oxid

DISTRIBUTION OF DNA DAMAGE REPAIR GENE POLYMORPHISM hOGG1, XRCC1 and p53 AMONG SICKLE CELL DISEASE PATIENTS IN INDIA

Background– Defect in DNA damage repair genes due to oxidative stress predispose the humans to malignancies. There are many cases of association of malignancies with sickle cell disease patients (SCD) throughout the world, the molecular cause of which has never been investigated. DNA damage repair genes such as  hOGG1, XRCC1 and p53 play significant role in repair of DNA damage during oxidative stress but the distribution and clinical effect of these genes are not known till date in SCD patients who are associated with oxidative stress related clinical complications.         Objective – The aim of the study was to characterize the distribution and clinical effect of DNA damage gene polymorphisms p53 (codon 72 Arg> Pro), hOGG1 (codon 326 Ser>Cyst) and XRCC1 (codons 194 Arg>Trp, codon 280 Arg> His, codon 399 Arg> Gln) among SCD patients of  central India.  Methods- A case control study of  250 SCD patients and 250 normal individuals were investigated by PCR-RFLP techniques.      Result- The prevalence of mutant alleles of hOGG1 gene, XRCC1 codon 280 Arg>His  were found to be significantly high among SCD patients as compared to controls. However, SCD patients did not show clinical association with any of these DNA repair gene polymorphisms.   Conclusion- This indicates that hOGG1, p53  and XRCC1 gene polymorphisms  may not have any clinical impact among SCD patients in India