The likely diagnosis of CVID was based on the following criteria: frequent bacterial infections (consequently leading to advanced chronic pulmonary disease and bronchiectasis), growth retardation and failure to thrive, myocardiopathy, hepatomegaly, autoimmune phenomena (similar to scleroderma), decreased levels of IgG, IgA, and IgM, absence of isohemagglutinin synthesis, and poor response to active immunization (tetanus toxoid). This evidence concerns the gene CD40LG and Failure to thrive.