Analysis of genes involved in immune response in children with HLH -- case series.

Background Hemophagocytic lymphohistiocytosis (HLH) is an excessive immune activation syndrome. The genetic studies on every patient diagnosed with HLH recently became a standard of care. The likelihood of identifying a gene mutation is highest in the youngest patients. Results [Four HLH patients had changes in the following five genes](mailto:peter.fritsch@medunigraz.at): [NLRP1 (c.923G>A)](mailto:peter.fritsch@medunigraz.at), [DOCK 8 (Dedicator of Cytokinesis 8) (c.3067A>G)](mailto:peter.fritsch@medunigraz.at), [AIRE gene (c.10G>A) and one in the RNASEH2B (c.649T>C)](mailto:peter.fritsch@medunigraz.at), [PSTPIP1 (c.1213C>T)](mailto:peter.fritsch@medunigraz.at). No mutations in genes previously associated with HLH syndrome were found. Conclusions [The described cases show that genetic analysis is helpful for the diagnosis of HLH in pediatric patients. The functional analysis of a putative mutation is essential for understanding the pathological mechanism; while not every change in DNA might be responsible for the disease. Each patient might have different mutations; however, they all develop the same clinical outcome. Disruption at different levels can result in a similar picture.](mailto:peter.fritsch@medunigraz.at)