Transfusion-dependent anemia, and cytopenia secondary to parvovirus B19 infection as the first manifestation of X-linked hyper immunoglobulin M immunodeficiency syndrome in two male patients in their third decade of life

We describe two male patients with unique mutation of the CD40L gene, unlike the classic presentation of X-linked hyper immunoglobulin M immunodeficiency syndrome (XHIGM syndrome), both were healthy until presenting in their early twenties with a challenging symptomatic transfusion-dependent anemia, investigations confirmed XHIGM syndrome with concurrent chronic parvovirus infection.