Table 1.
Characteristics of the study participants
| Characteristic | All Carriers | C9orf72+ | GRN+ | MAPT+ | Non-Carriers | p-value | Pairwise Comparisons |
|---|---|---|---|---|---|---|---|
| Sample Size | 796 | 347 | 281 | 168 | 412 | ||
| ALLFTD Sample Size | 275 | 127 | 68 | 80 | 161 | ||
| GENFI Sample Size | 521 | 220 | 213 | 88 | 251 | ||
| Age - yr (mean(SD)) | 50.2 (13.9) | 51.2 (13.7) | 52.2 (13.7) | 44.9 (13.3) | 45.9 (13.0) | <0.001 | (NC = MAPT) < (C9=GRN) |
| Female - n (%) | 447 (56.1%) | 188 (54.2%) | 167 (59.4%) | 92 (54.8%) | 239 (58.0%) | 0.51 | |
| Education - yr | 14.4 (3.2) | 14.5 (3.0) | 14.2 (3.4) | 14.7 (3.0) | 14.8 (2.9) | 0.07 | |
| Visits (total number) | 2.1 (1.1) | 2.0 (1.0) | 2.1 (1.1) | 2.5 (1.2) | 2.2 (1.1) | <0.001 | (C9=GRN,NC=GRN,C9<NC)< MAPT |
| N with 1 visit | 292 | 135 | 114 | 43 | 137 | ||
| N with 2 visits | 233 | 120 | 68 | 45 | 106 | ||
| N with 3 visits | 158 | 53 | 57 | 48 | 118 | ||
| N with ≥4 visits | 113 | 39 | 42 | 32 | 51 | ||
| Total number of observations | 1,695 | 690 | 592 | 413 | 910 | ||
| Follow-up Length (if > 1 visit) – yr | 2.0 (0.9) | 1.9 (0.9) | 2.1 (0.9) | 2.2 (0.9) | 2.2 (0.8) | <0.001 | C9< (GRN = MAPT = NC ) |
| Race - n (%) | |||||||
| White | 776 (97.5%) | 342 (98.6%) | 274 (97.5%) | 160 (95.2%) | 404 (98.0%) | 0.11 | |
| Non-White^ | 19 (2.4%) | 4 (1.2%) | 7 (2.5%) | 8 (4.8%) | 6 (1.5%) | ||
| Unknown | 1 (0.1%) | 1 (0.3%) | 0 | 0 | 2 (0.5%) | ||
| CDR®+NACC-FTLD Global- n (%) | |||||||
| 0 | 433 (54.4%) | 171 (49.3%) | 168 (59.8%) | 94 (56.0%) | 412 (100%) | 0.03^^ | C9<GRN, C9=MAPT, GRN=MAPT |
| 0.5 | 127 (16.0%) | 61 (17.6%) | 39 (13.9%) | 27 (16.1%) | NA | 0.45 | |
| ≥ 1 | 236 (29.7%) | 115 (33.1%) | 74 (26.3%) | 47 (28.0%) | NA | 0.16 | |
| Estimated Years Since Onset * | 4.4 (4.7) | 5 (4.7) | 2.7 (2.4) | 6 (7.8) | NA | <0.001 | GRN< C9, GRN < MAPT, C9 = MAPT |
| Symptomatic Diagnoses - n (%) | |||||||
| bvFTD | 162 (68.6%) | 85 (73.9%) | 38 (51.4%) | 39 (83.0%) | NA | <0.001 | GRN < (C9 = MAPT) |
| PPA | 30 (12.7%) | 4 (3.5%) | 25 (33.8%) | 1 (2.1%) | NA | <0.001 | (C9 = MAPT) < GRN |
| CBS | 2 (0.9%) | -- | 2 (2.7%) | -- | NA | 0.13 | |
| PSP | 3 (1.3%) | 1 (0.9%) | 1 (1.4%) | 1 (2.1%) | NA | 0.78 | |
| ALS | 4 (1.7%) | 4 (3.5%) | -- | -- | NA | 0.14 | |
| FTD-MND | 11 (4.7%) | 11 (9.6%) | -- | -- | NA | 0.002 | (GRN=MAPT) < C9 |
| MCI | 4 (1.7%) | 2 (1.7%) | 1 (1.4%) | 1 (2.1%) | NA | 1.0 | |
| AD Dementia | 5 (2.1%) | 1 (0.9%) | 3 (4.1%) | 1 (2.1%) | NA | 0.35 | |
| Other** | 4 (1.7%) | 3 (2.6%) | 1 (1.4%) | 1 (2.1%) | NA | NA | |
| Missing | 9 (3.8%) | 4 (3.5%) | 2 (2.7%) | 3 (6.4%) | NA | NA |
Note. Demographics were calculated using baseline values. Demographic variables and other participant characteristics were compared across genetic groups and controls using regression with pairwise group contrasts for most variables. Sex, race, CDR®+NACC-FTLD, and diagnostic categories were compared using chi-square with Bonferroni-adjusted pairwise comparisons when the omnibus test was significant. For chi-square tests in which any bins were < 10, the Fisher’s exact test was used. All tests were two-sided. Symptomatic clinical diagnoses were calculated in those with a CDR®+NACC FTLD Global ≥ 1
Due to the small number of non-White participants in this sample, a single bin was used to protect participants’ identities.
Controls not included in pairwise comparisons for CDR®+NACC FTLD
Median (IQR) of baseline values for symptomatic cases based on clinician-reported age of onset.
Other diagnoses include dementia not otherwise specified (n=2) or the clinician marked “other” without entering additional information.
Abbreviations: CDR®+NACC-FTLD: Clinical Dementia Rating Scale plus National Alzheimer’s Coordinating Center Frontotemporal Lobar Degeneration Module; bvFTD: Behavioral Variant Frontotemporal Dementia; PPA: Primary Progressive Aphasia; CBS: Corticobasal Syndrome; PSP: Progressive Supranuclear Palsy Syndrome; ALS: Amyotrophic Lateral Sclerosis; MND: Motor Neuron Disease; MCI: Mild Cognitive Impairment; AD: Alzheimer’s Disease