Familial hemophagocytic lymphohistiocytosis and X-linked lymphoproliferative disease.

Familial hemophagocytic lymphohistiocytosis and X-linked lymphoproliferative disease are rare, fatal, inherited immune deficiency disorders. Both diagnoses are used to describe patients who are affected by several known or presumed genetic mutations that, in common, predispose patients to the development of hemophagocytic lymphohistiocytosis. Many pivotal advances have been made in recent years with regard to our understanding and treatment of these diseases. Here, we will describe the genetic and functional bases of these diseases, highlight their clinical manifestations, and discuss current diagnostic and therapeutic strategies.