<unk>  (also known as Duncan<unk>  or Purtilo syndrome and abbreviated as<unk>  is a lymphoproliferative disorder, usually caused by SH2DIA gene mutations in males.<unk> -positive individuals experience immune system deficiencies that render them unable to effectively respond to the Epstein-Barr virus (EBV), a common virus in humans that typically induces mild symptoms or infectious mononucleosis (IM) in patients. There are two currently known variations of the disorder, known as<unk> 1 <unk>  Type 1) and<unk> 2.<unk> 1 is estimated to occur in approximately one in every million males, while<unk> 2 is rarer, estimated to occur in one of every five million males. Due to therapies such as chemotherapy and stem cell transplants, the survival rate of<unk> 1 has increased dramatically since its discovery in the 1970s.
X-linked lymphoproliferative disease
Autoimmune lymphoproliferative syndrome
Adult-onset immunodeficiency syndrome
Primary immunodeficiency
RAS-associated autoimmune leukoproliferative disorder
X-linked severe combined immunodeficiency
Nodal marginal zone B cell lymphoma
Splenic marginal zone lymphoma