Association between TGF-β1 rs1800471 polymorphism and human herpesvirus-6A infection with non-Hodgkin lymphoma in an Iraqi cohort

Objective: Non-Hodgkin lymphoma (NHL) is a heterogeneous group of malignancies with a complex aetiology involving genetic and viral factors. This study aimed to investigate the association of the Transforming Growth Factor-Beta 1 (*TGF-β1*) rs1800471 polymorphism and active Human Herpesvirus-6A (HHV-6A) infection with NHL risk in an Iraqi population. Methods: A case-control study was conducted involving 100 NHL patients and 100 age- and sex-matched apparently healthy controls (AHC). Genomic DNA was isolated from blood samples. The *TGF-β1* rs1800471 polymorphism was genotyped using Polymerase Chain Reaction (PCR) followed by Sanger sequencing. The presence of HHV-6A DNA was detected using virus-specific PCR. Results: HHV-6A DNA was detected in 29% of NHL patients and none of the controls (p=0.03). Genotype analysis of a representative subset (40 patients, 20 controls) revealed that the GG genotype of *TGF-β1* rs1800471 was more frequent in patients (32.5%) than in controls (10%), showing a significant association (p=0.04). The G allele was also significantly more prevalent in patients (47.5%) compared to controls (37.5%) (p=0.04). A significant positive correlation was observed between the *TGF-β1* polymorphism and patient age (r=0.722, p=0.03), but no correlation was found with HHV-6A status. Conclusions: Our findings suggest that both the *TGF-β1* rs1800471 G allele and active HHV-6A infection are potential risk factors associated with NHL development in this cohort. Further large-scale studies are warranted to confirm these associations and elucidate the underlying mechanisms.