Fig. 2.

CSF levels of sAPPα, sAPPβ, Aβ₃₈, Aβ₄₀ and Aβ₄₂ in carriers of three FAD mutations. Scatter plots showing levels of sAPPα, sAPPβ, Aβ₃₈, Aβ₄₀ and Aβ₄₂ in carriers of three different mutations leading to FAD compared with healthy family members (NC). The mutation carriers were compared with the NC as one group (MC) and by type of mutation (APPswe, APParc and PSEN1). Only carriers of the APParc and PSEN1 mutations are included in the calculation of the mean level of sAPPβ. The biomarker levels in the NC group were normally distributed, except for sAPPβ. Thus, the Mann–Whitney U test was used when comparing sAPPβ between groups. Also, the Mann–Whitney U test was used when comparing the APParc and PSEN1 carriers with the NC due to the small sample sizes of these two MC groups. The unpaired t test was used for the rest of the data, except when comparing Aβ₄₂ between the NC and MC and comparing sAPPα between the NC and APPswe (here we used the Mann–Whitney U test because these data were not normally distributed). Aβ amyloid beta, MC mutation carriers, NC noncarriers