TP53 Gene 72 Arg/Pro (rs1042522) Single Nucleotide Polymorphism Contribute to Increase the Risk of B-Chronic Lymphocytic Leukemia in the Sudanese Population

OBJECTIVE:: This study aimed at exploring the association of TP53 72Arg/Pro polymorphism and Risk of Chronic Lymphocytic Leukemia and to assess the correlation between TP53 72Arg/Pro polymorphism and clinical parameter, hematological profile and some biological prognostic markers among Sudanese patients with chronic lymphocytic leukemia. METHODS: A case-control study was conducted in Khartoum state, Sudan, during the period from April 2017 to April 2018, involved 110 B-CLL patients and 80 healthy volunteers as a control group. Physical examination, Complete Blood Count and Immunophenotype were performed in all patients to confirm the diagnosis. Clinical staging such as Rai and Binet were studied. CD38 and ZAP70 were performed by Flow Cytometry. Blood samples were collected from all participants; DNA was extracted by using ANALYTIKJENA Blood DNA Extraction Kit (Germany) and analyzed TP53 codon 72Arg/Pro Polymorphism by using AS-PCR. The statistical analysis was performed using SPSS version 23.0 software (Chicago, IL, USA). RESULTS: the Arg/Pro was the most frequent genotype in B-CLL patients(50%), followed by Arg/Arg (25.5%) and Pro/Pro (24.5%), whereas in healthy control group Arg/Pro was the most frequent (47.5%), followed by Arg/Arg (45%) and Pro/Pro (7.5%). Our data indicate a higher frequency of homozygous Pro/Pro in the B-CLL patients as compared to controls with an OR of 4.01 for the Pro/Pro genotype and lower frequency of Arg/Arg genotype in CLL patients as compared to controls with an OR of .42 for the Arg/Arg genotype. Also, the Pro allele showed higher risk than Arg allele (P value=0.000, OR 2.23, 95% CI=1.45-3.41). No significant association between gender, clinical staging systems (Rai, Binet), biological prognostic markers (CD38 expression or ZAP70 expression), and TP53 codon 72Arg/Pro polymorphisms, except Arg/Arg genotype tended to be associated with younger age (P =0.04). CONCLUSION: Our data suggested that Pro/Pro genotype contribute to increased susceptibility to B-Chronic Lymphocytic Leukemia risk in our population tenfold higher than those had Arg/Arg genotype.