These analyses showed that there was no difference in gene polymorphisms of TGF-β1 -509 T vs. C between Mixed-LC and HCV-LC groups (I2 = 0%, p = 0.660), while there was a significant difference of IFN-γ + 874 T vs. A between HCV-LC and HBV-LC groups (I2 = 88%, p = 0.004) and heterogeneity was reduced in the subgroup of the HCV-LC group (Figure 3). Here, IFNG is linked to laryngotracheoesophageal cleft.