IGHG3 and infection: Additionally, De Souza-e-Silva (2013) studied the association between clinical signs of congenital toxoplasmosis and IgG subclasses found in newborns and observed that anti-T. gondii IgG3 was associated with newborns without neurologic damage, highlighting the importance of this immunoglobulin in protecting the newborn from infection by T. gondii [46].