Immunopathology & Immunotherapy

The most striking observation is the strong majority of male patients in the group of children with primary hypogammaglobulinemia (n=1292, 63%). This male predominance was observed in each of the 18 countries involved. The boys were younger at diagnosis (mean age males 5.3 years; mean age females 5.8 years). Moreover, one or more complications were more frequently reported in boys (12%) as compared to girls (5%). The male predominance suggests that patients with an undetected or unknown X-linked genetic cause are included in this group of children registered as primary hypogammaglobulinemia.