Table 1.
Characteristics of the twin pairs discordant for SSc used for this analysis
| Pair | Zygosity | Subtype | Gender | Autoantibody | Organ involvement |
|---|---|---|---|---|---|
| 1 | MZ | dcSSc | F/F | RNA pol | JT, GI, DU, RN |
| 2 | MZ | dcSSc | F/F | ATA | JT, GI, DU |
| 3 | MZ | dcSSc | F/F | RNA pol | JT |
| 4 | MZ | dcSSc | F/F | RNA pol | JT, LN, RN |
| 5 | MZ | dcSSc | F/F | U3 | JT |
| 6 | DZ | dcSSc | F/F | RNA pol | JT, GI, DU |
| 7 | MZ | lcSSc | F/F | U1 | GI |
| 8 | MZ | lcSSc | F/F | PL-7 | JT, GI, LN |
| 9 | MZ | lcSSc | F/F | U3 | JT, GI |
| 10 | DZ | lcSSc | F/F | ACA | JT, DU |
| 11 | DZ | dcSSc | F/F | ATA | JT, GI, DU, LN |
| 12 | MZ | dcSSc | F/F | Unknown | JT, GI, LN |
| 13 | MZ | dcSSc | F/F | RNA pol | N/A |
| 14 | DZ | lcSSc | F/F | ACA | JT |
| 15 | DZ | lcSSc | F/F | RNA pol | N/A |
| 16 | DZ | lcSSc | F/M | ATA | N/A |
| 17 | DZ | lcSSc | F/F | PM-Scl | JT, GI |
| 18 | DZ | lcSSc | F/F | U1 | JT |
| 19 | MZ | lcSSc | F/F | ACA | JT, GI, DU |
| 20 | MZ | lcSSc | F/F | U3 | GI, DU |
| 21 | MZ | lcSSc | F/F | ATA | N/A |
| 22 | MZ | lcSSc | M/M | RNA pol | N/A |
| 23 | MZ | lcSSc | F/F | ACA | N/A |
| 24 | MZ | lcSSc | F/F | ACA | N/A |
| 25 | MZ | lcSSc | F/F | ACA | N/A |
| 26 | MZ | lcSSc | F/F | ACA | N/A |
| 27 | MZ | lcSSc | F/F | U1 | N/A |
MZ monozygotic, DZ dizygotic, F female, M male, ACA anticentromere, RNA pol anti-RNA polymerases, ATA anti-topoisomerase I, U1 anti-U1 RNP, U3 anti-U3 RNP, PL-7 anti-PL-7, PM-Scl anti-PM-Scl, Unknown autoantibodies did not recognize known autoantigens JT joint or tendon GI gastrointestinal, DU digital ulcers, LN lung, RN renal, N/A data not available