Niemann-Pick Disease Type B

Niemann-Pick disease type B (NPDB) is caused by deficient activity of sphingomyelin phosphodiesterase leading to the accumulation of sphingomyelin and other lipids, primarily within macrophages. The disease is characterised by hepatosplenomegaly, a bleeding tendency, interstitial lung disease and an atherogenic lipid profile. The diagnosis of NPDB is usually made in childhood after organomegaly is noted, and patients often survive into adulthood. The diagnostic work up includes enzymatic determination of sphingomyelinase activity, mutational analysis and screening and/or quantification for target organ involvement. NPDB has a variable clinical expression and may be a life-limiting disorder with significant morbidity and mortality. There is no disease specific therapy yet and hence management is symptomatic with particular attention to treating the long term complications of the disease.