In view of this constellation, it is interesting to note that patient 1 with no somatic reversion in CD4+ T-cells presented in childhood with recurrent infections of the respiratory tract and received IVIG substitution therapy whereas patient 2 with somatic chimerism in CD4+ T-cells showed no clinical sign of immunodeficiency and merely laboratory investigations showed CD4+ lymphocytopenia and IgG subclass deficiency. This evidence concerns the gene CD4 and lymphopenia.