CD4 and lymphopenia: In our cohort, the two adult patients (STAT1L283M P2 and STAT1L351F P3, as named in Dotta et al. [26, 27]), had lymphopenia (absolute total lymphocyte count below 1.000 cells/mmc), while the three other adolescent/young adult patients (STAT1T385M P4, STAT1T385M P5 and STAT1L400V P6) presented borderline counts of total lymphocytes, all with a consensual reduction of both CD4 + and CD8 + subsets.