The relationship of thrombocytopenia in cases of TAPVC showed a significant p-value of 0.002 compared to the non-thrombocytic TAPVC cases. The hemoglobin concentration among those suffering from thrombocytopenia was 15.65±3.96, while the patients with no thrombocytopenia had an Hb concentration of 13.87±3.18. This evidence concerns the gene GSTM1 and Thrombocytopenia.