Estimation of the number of inherited prion disease mutation carriers in the UK

225 patients, with 21 different IPD mutations were identified in the sample, varying in frequency (Fig. 1) and assumed to be fully penetrant and dominant for the purposes of the study, and derived from 116 kindreds and 151 3-generation families (Supplementary Table 1). Cumulatively, the 8 most common mutations account for over 90% of IPD cases, in order of frequency, p.P102L, 6-OPRI, E200K, A117V, 4-OPRI, D178N, 5-OPRI, and Y163X. We considered a capture period of 1990 to 2007 and recapture period of 2008 to 2019. These durations were chosen to approximate the numbers of cases in the capture and recapture periods as the annual diagnosis of IPD has increased over time. The capture-recapture method estimated 303 (95% CI 222–384) UK 3-generation IPD families (observed n = 151); 264 kindreds (observed n = 116); and 24 IPD mutations (observed n = 21) (Table 1).