X-linked thrombocytopenia (THC1/XLT)

X-linked thrombocytopenia (XLT) is a rare bleeding disorder characterized by isolated thrombocytopenia with small-sized platelets. XLT is a milder clinical variant of Wiskott-Aldrich syndrome (WAS), which is characterized by the clinical triad of eczema, susceptibility to infection and thrombocytopenia, while patients with XLT only present with thrombocytopenia. XLT is caused by a mutation in the WAS gene.