Background: T-box-transcription-factor-20 (TBX20) is a major type of T-box protein family that plays a plausible function in the optimum functional and developmental of cardiac tissues. This work aimed to assess the contribution of TBX20 gene polymorphisms with elevated risk of congenital heart disease (CHD) among Egyptian subjects.  Methods: This case-controlled study consisted of 175 participants [75 patients diagnosed with CHD along with 100 unrelated healthy controls], matched with age and gender. The genetic variant for TBX20* was genotyped and characterized with the aid of the polymerase chain reaction-restriction fragment-length-polymorphism (PCR-RFLP) technique.
Results: Our findings revealed a higher frequency of TBX20*(T/T) genotype among CHD patients compared with healthy controls. Additionally, testing genetic association models revealed a significant association with protection against CHD in the recessive model. This might imply this rare genotype is a predisposing factor to protect against congenital heart disease. Moreover, the TBX20(C/C) genotype exhibited higher prevalence among males than females among CHD compared to unrelated healthy controls. On the contrary, the frequency of TBX20*(T/T) genotype was higher among both males and females than healthy controls. The frequency of TBX20*(C/C) genotype within TOF cases was higher in CHD cases compared to healthy controls. However, the frequency of TBX20*(T/T) genotype was significantly associated with VSD cases compared to healthy controls.
Conclusions: In conclusions, our findings revealed the protective function of the TBX20*rs3999950 gene variant against the development of congenital heart diseases among Egyptian subjects.