Homologous G776G Variant of Transcobalamin-II Gene is Linked to Vitamin B12 Deficiency.

Vitamin B12 (Cobalamin) deficiency, due to improper internalization of cobalamin, is a metabolic disorder prevalent in impoverished and elderly populations and is associated with megaloblastic anemia and dementia. It has been suggested that mutations in transcobalamin II (TCN2) or gastric intrinsic factor (GIF) proteins can alter their binding efficiency to cobalamin or reduce the ability of their receptors to internalize them. In this case-control study, the correlation between vitamin B12 deficiency and alternative alleles of TCN2 and GIF was investigated in a Jordanian population. One hundred individuals with vitamin B12 deficiency (B12 < 200 mg/mL) were enrolled in our study to evaluate the TCN2 and GIF polymorphisms. The control group (B12 > 200 mg/mL) included 100 individuals. Our results indicated a significant association between the homologous variant of the TCN2 gene (G776G) and vitamin B12 deficiency, and an intermediate phenotype in heterozygous individuals (p < 0.001, OR = 5.6, 95% CI = 2.95 to 10.63). The GIF gene, however, showed no correlation between the A68G variant and vitamin B12 deficiency (p = 0.2). This study expounds the association of TCN2 polymorphism with cobalamin levels in a Jordanian population and highlights the necessity of further studies to elucidate the molecular basis and impact of TCN2 and GIF genes polymorphisms on vitamin B12 deficiency and associated disorders.

RAD51-UTR haplotype genetic polymorphisms and susceptibility to breast cancer in women from Jordanian population.

BACKGROUND: Genetic predisposition to breast cancer (BC) has been extensively explored to achieve an enhanced understanding of the biology of BC. Targeting candidate genes to screen different genetic variants such as RAD51 gene that plays a critical role in DNA repair pathways including the double-strand break repair system is an important task. AIM: To study several single nucleotide polymorphisms (SNPs) within RAD51-UTR gene and to find their relationship with BC risk and prognosis among Jordanian females. MATERIALS AND METHODS: In this case-control study, DNA sequencing technique was used to screen SNPs within the untranslated region (UTR) of RAD51 in 206 cases and 185 controls and the resulting data were statistically analyzed using different types of genetic analyses. Patients' clinical and pathological features were obtained from their medical records to perform genotype-phenotype association analysis. RESULTS: Our findings show a significant association between both SNPs rs528590644, rs1801320 and BC risk (p = 0.016). We estimated the correlation between many of BC prognostic factors and BC risk, and we found an association between rs1801321 and age at first menstruation (p = 0.032) in addition to a strong correlation between age at BC diagnosis and rs1801320 (p = 0.008). CONCLUSION: RAD51-UTR polymorphisms may be involved in BC development and progression.