CD27 and common variable immunodeficiency: This presentation of NRH expands the phenotypic diversity of the few patients with CD3G mutations who have an obvious decrease in class-switch memory B cells and meet the criteria for the CVID phenotype, as in the Paris MB0 classification (6.8% CD27 of total B cells <11%), Freiburg Ib classification (0.1% switched CD27IgD– of total B cells <0.4% and 15.5% CD21 low of total B cells <20%), and EuroClass group smB-CD21low (0.3% switched memory cells ≤2% and 15.5% CD21lowB cells >10%) (27).