X-linked lymphoproliferative disease

X-linked lymphoproliferative disease
Other names	Duncan disease, Purtilo syndrome
Specialty	Hematology
Symptoms	Reduced resistance to the Epstein-Barr virus (EBV), leading to infectious mononucleosis, hemophagocytic lymphohistiocytosis (HLH), dysgammaglobulinemia, non-Hodgkin lymphoma, aplastic anemia, vasculitis, chronic gastritis, skin lesions
Duration	Life long
Causes	Genetic (X-linked recessive)
Treatment	Chemotherapy, stem cell transplants
Frequency	1 in 1,000,000 males (XLP1); 1 in 5,000,000 males (XLP2)

X-linked lymphoproliferative disease (also known as Duncan disease^[1]: 86 or Purtilo syndrome^[2] and abbreviated as XLP^[3]) is a lymphoproliferative disorder,^[4] usually caused by SH2DIA gene mutations in males. XLP-positive individuals experience immune system deficiencies that render them unable to effectively respond to the Epstein-Barr virus (EBV),^[3] a common virus in humans that typically induces mild symptoms or infectious mononucleosis (IM) in patients.^[5] There are two currently known variations of the disorder, known as XLP1 (XLP Type 1) and XLP2. XLP1 is estimated to occur in approximately one in every million males, while XLP2 is rarer, estimated to occur in one of every five million males.^[6] Due to therapies such as chemotherapy and stem cell transplants, the survival rate of XLP1 has increased dramatically since its discovery in the 1970s.^[3][7]