Ferritin levels above 10,000 microg/L appear to be specific and sensitive for HLH. In patients without a significant medical history and a new onset of febrile illness with highly elevated ferritin levels, the diagnosis of HLH should be evaluated.

Mutations predicted to result in the loss of RECQL4 protein function occurred in approximately two-thirds of RTS patients and are associated with risk of osteosarcoma. Molecular diagnosis has the potential to identify those children with RTS who are at high risk of this cancer.

Infants with CF incurring respiratory virus infection are at significant risk for LRTI, for hospitalization, and for deterioration in lung function that persists months after the acute illness.

No abstract