Fig. 6. Cryptic HDGFL2 can be detected by MSD assay in plasma of both presymptomatic and symptomatic C9orf72 mutation carriers.
a, In the symptomatic group (mean 2.1, s.d. 2.3, range 0.71–9.80), 17 of 37 (45.9%) plasma samples had cryptic HDGFL2 plasma:diluent MSD signal ratios >1. In the presymptomatic group (mean 1.1, s.d. 0.60, range 0.68–3.70), nine of 29 (31.0%) plasma samples had plasma:diluent signal ratios >1. The difference between symptomatic and presymptomatic C9orf72 mutation carriers was not significant (z = −0.82, P = 0.42, Mann–Whitney U-test). Cryptic HDGFL2 levels were also measured in older controls with NPH (n = 13, mean 1.6, s.d. 1.6, range 0.64–6.70) and in younger controls with migraine (n = 17, mean 1.0, s.d. 0.25, range 0.69–1.40). Data presented as mean ± s.d. Data points represent individual plasma samples. b, Plasma:diluent signal ratios were significantly correlated with CSF:diluent signal ratios from matching CSF samples (r = 0.83, P < 1.0 × 10−15, Pearson, two-tailed).