haemophagocytic lymphohistiocytosis, familial, type 5

haemophagocytic lymphohistiocytosis, familial, type 5

A rare autosomal recessive disorder (OMIM:613101) 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, cytopenia; less commmonly, neurologic defects ranging from irritability and hypotonia to seizures, cranial nerve deficits and ataxia.

Molecular pathology
Defects in STXBP2, which encodes a protein involved in intracellular vesicle trafficking from the Golgi apparatus to the plasma membrane, cause familial haemophagocytic lymphohistiocytosis type 5.