Indeed, it should be kept in mind that, especially in very young children, where pathognomonic signs of Hyper-IgE syndromes may be absent, the clinical features of MyD88 deficiency and other Hyper-IgE syndromes may be overlapping since both the conditions may present with early onset invasive suppurative infections with a scarce inflammatory component. The gene discussed is MYD88; the disease is hyper-IgE syndrome.