Mortality in neurofibromatosis 1: in North West England: an assessment of actuarial survival in a region of the UK since 1989.

Neurofibromatosis 1 (NF1) is a comparatively common autosomal dominant disorder. However, relatively few studies have assessed lifetime risk; and information about the effect of NF1 on mortality remains uncertain. NF1 patients were identified using The North West regional family Genetic Register, which covers the 4.1 million people living in North West England, including the regions of Greater Manchester, Cheshire and Cumbria. Data relating to tumours and malignancies were obtained from The North West Cancer Intelligence Service. Death data for the general North West population were obtained from the Office of National Statistics. We identified 1186 individuals with NF1, of whom 1023 lived within the strict regional boundaries (constituting a region of North West England bound by The Pennines to the east and Irish Sea to the west, but excluding the conurbation of Liverpool (Merseyside) and the Wirral peninsula) and 131 had died. MPNST and glioma were found to be the two most common causes of reduced life expectancy among NF1 patients. In Kaplan-Meier analyses the median survival for NF1 patients was shown to be 71.5 years, with women living ∼7.4 years longer than men. On average both men and women lived ∼8 years less than their counterparts in the general population. Reduction in life expectancy for NF1 patients was found to be much lower (8 years) than the previously estimated 15-year decrease. Limitations relating to the underreporting of NF1 on death certificates were once again highlighted and should be considered in future investigations.