label: familial hemophagocytic lymphohistiocytosis type 1
label_lc: familial hemophagocytic lymphohistiocytosis type 1
description: "Familial Hemophagocytic lymphohistiocytosis (FHL) is a rare primary immunodeficiency characterized by a macrophage activation syndrome with an onset usually occurring within a few months or less common several years after birth."