hemophagocytic lymphohistiocytosis, familial, type 4

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hemophagocytic lymphohistiocytosis, familial, type 4

A rare autosomal recessive disorder (OMIM:603552) characterised by immune dysregulation with hypercytokinaemia, defective NK cell activity, and massive infiltration of several organs by activated lymphocytes and macrophages.

Clinical findings
Fever, hepatosplenomegaly, cytopenias, hypertriglyceridemia, hypofibrinogenaemia; less commmonly, neurologic defects ranging from irritability and hypotonia to seizures, cranial nerve deficits and ataxia.

Molecular pathology
Caused by defects in STX11, which encodes a protein that plays a role in the targeting and fusion of intracellular transport vesicles.