However, our previous study with detection of CMV IgG and IgM in longitudinal serum samples at ages of 1, 3.5, 8, and 24 months in a cohort of infants showed that CMV IgM was mostly positive (83.3%) at ages of 1 and 3.5 months (4), indicating the postnatal CMV infection mostly occurs before 3.5 months age. The gene discussed is CD40LG; the disease is cytomegalovirus infection.