English

Abstract

BACKGROUND Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C variants are considered as potential genetic risk factors for vaso-occlusive complications in sickle cell disorder (SCD). The purpose of the study was to determine the interaction of the combined haplotypes on the clinical presentations in children with sickle cell disorder. METHODS A cross-sectional study was conducted on 249 children, confirmed for sickle cell disorder. Clinical details and frequencies of clinical episodes in the past one year were noted and a severity index number was allotted to each child and evaluated for their relationship with the combined haplotypes of C677T and A1298C single nucleotide polymorphisms genotyped by real-time PCR. RESULTS The frequency for 677T / 1298A haplotype was 46.4 % and that of 677C / 1298C was 12.4 %. The three variant combined haplotypes had higher plasma homocysteine values than the wild 677C / 1298A haplotypes (P < 0.001). Clinical events like vasoocclusive crisis (VOC), homocysteinemia, hospitalization frequency and SI were found significantly related among the children in sickle cell trait (SCT) group (P < 0.001) but not so in SCD group. Chances for anemia was 1.93 times more in presence of dual variant alleles (95 %CI: 0.95 to 3.92, P = 0.07) in SCT. The 677T / 1298C haplotype accounted for higher SI was 7.85 times more than the wild haplotypic children even in SCT children and 1.67 times in SCD children. CONCLUSIONS Presence of the variant haplotypes had significant implication on crisis events in children with sickle cell trait and make them more prone for the clinical severity. A preliminary allelic screening might be helpful in them. KEY WORDS Dual Variant Alleles, Heterozygous, Homozygous, MTHFR, Variant Haplotypes