Background: The role of NFATC genes expression in BAV progression is not fully understood. Aim of study is to determine the significance of NFATC1 and NFATC4 gene expression for myocardial changes in children with BAV. Methods: In 47 children with BAV the standard Doppler echocar-digraphic characteristics were detected and the expression of the NFATC1 and NFATC4 genes was studied. Results: PWTd, AoPPG, in BAV patients were significantly higher compared to healthy controls (PWTd median(min-max) 9 (7-10) mm vs 7 (6-8) mm), AoPPG median (min-max) 7,79 (2,98-15,09) mm Hg vs 2,94 (2,42-3,72) mm Hg. Expression of NFATC1 gene in BAV children was significantly higher compared to NFATC4 (NFATC1 median (min-max) 70,88 (8,79-106,51) e.u. vs 7,72 (1,74-22,67) e.u., respectively p<0,05). Significant correlation of NFATC1 expression with Ao found (R=+0,53, p<0,05). In BAV patients with PWTd > 8 mm and Ao> 21 mm the NFATC1 expression was significantly higher compare to those with PWTd< =8 mm and Ao<=21 mm NFATC1 median (min-max) 45,49 (5,01-101,52) e.u. vs 15,53 (2,36-44,40) e.u., p<0.05 and 81.11 (20.27-101.10) e.u. mm vs 12.16 (2,40-45.49) e.u., p<0.05, respectively) Conclusion: in children with BAV the high expression of the NFATC1 calcineurin signalling pathway gene is associated with elevated PWTd and Ao.