Demographic characteristics of the study cohorts
| C9-ALS | C9-FTD | CAR | P-value | |
| iTRAQ discovery cohort | ||||
| n | 16 | 8 | 11 | – |
| Gender (male/female) | 10/6 | 5/3 | 2/9 | 0.0515 |
| Age | 60 (51–67) | 56 (46–60) | 46 (42–49) | 0.0061 |
| ALSFRS-R | 39.5 (34.75–42.75) | – | – | – |
| FTLD-CDR | – | 6.5 (4.13–11.38) | – | – |
| C9-ALS | sALS | C9-FTD | sFTD | C9-ALS/bvFTD | CAR | CON-o | CON-y | P-value* | |
| MRM validation cohort | |||||||||
| n | 28 | 27 | 18 | 21 | 5 | 28 | 17 | 12 | – |
| Gender (male/female) | 15/13 | 17/10 | 12/6 | 14/7 | 2/3 | 8/20 | 10/7 | 3/9 | 0.0627 (0.6979) |
| Age | 59 (55–67) | 60 (51–66) | 57 (47–60) | 63 (59–68) | 64 (64–66) | 45 (38–49) | 58 (52–64) | 46 (43–51) | <0.0001 (0.2419) |
| Study site: Ulm/Rotterdam | 27/1 | 27/0 | 13/5† | 21/0† | 5/0† | 14/14 | 17/0 | 12/0 | – |
| ALSFRS-R | 39.5 (35.25–41.75)‡ | 44 (40–46) | – | – | – | – | – | – | – |
| FTLD-CDR | – | – | 5.5 (3.63–10) | 5.5 (4.5–6.75) | – | – | – | – | – |
| C9-ALS | C9-FTD | C9-ALS/ bvFTD | CAR | CON-o | CON-y | P-value* | |
| SIMOA validation cohort | |||||||
| n | 26 | 13 | 5 | 13 | 17 | 10 | – |
| Gender (male/female) | 15/11 | 8/5 | 2/3 | 3/10 | 10/7 | 2/8 | 0.1000 (0.8673) |
| Age | 61 (55–67) | 56 (45–60) | 64 (64–66) | 47 (43–51) | 58 (52–64) | 48 (43–51) | <0.0001 (0.0928) |
| ALSFRS-R | 39.5 (35.25–41.75)‡ | – | – | – | – | – | – |
| FTLD-CDR | – | 6 (4–8.5) | – | – | – | – | – |
Values are given in median and IQR in parentheses. Kruskal-Wallis test and Dunn’s post hoc test were used to test for age and χ2 test was used to test for gender differences.
*P-value in parentheses after testing between the groups C9-ALS, C9-FTD, C9-ALS/bvFTD and CON-o.
†Study site: FTLD Consortium/Rotterdam.
‡ALSFRS-R scores were available from 14 patients.
ALSFRS-R, Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised; C9-ALS, amyotrophic lateral sclerosis patients with C9orf72 hexanucleotide repeat expansion; CAR, C9orf72 hexanucleotide repeat expansion carriers; C9-FTD, frontotemporal dementia patients with C9orf72 hexanucleotide repeat expansion; CON-o, control-old group; CON-y, control-young group; FTLD-CDR, FTLD-Clinical Dementia Rating scale; iTRAQ, isobaric tags for relative and absolute quantitation; sALS, sporadic amyotrophic lateral sclerosis; sFTD, sporadic frontotemporal dementia; SIMOA, single-molecule array.