Disease course within sibships
| Disease course | Frequency | Dichotomised disease course | Frequency |
| RRv RR | 84 | ||
| RRv RR-P | 68.3 | ||
| RR* v RR* | 191.7 | ||
| RRv P | 33.7 | ||
| RR* v P | 60.7 | ||
| RR-Pv RR-P | 39.3 | ||
| Pv P | 9.7 | ||
| RR-Pv P | 27 | ||
| Pv P | 9.7 |
RR=Relapsing-remitting; P=primary progressive; RR-P=secondary progressive.