Table 3.
Characteristics of the three clusters
| Variable | Cluster 1 (n = 6) |
Cluster 2 (n = 22) |
Cluster 3 (n = 17) |
P-value |
|---|---|---|---|---|
| Age | 28 (26–38) | 42.5 (26.75–48) | 38 (30.5–43.5) | 0.29 |
| Mutation | 0.03 | |||
| Deletions 45-x | 1 (17) | 17 (77.27) | 11 (64.44) | |
| Deletions distal to exon 45 | 0 (0) | 1 (4.55) | 2 (611.76) | |
| Mutations proximal to exon 45 | 5 (83) | 4 (18.18) | 4 (23.53) | |
| BMI | 21.40 (30.36–22.61) | 22.10 (20.11–24.85) | 24.02 (21.36–28.48) | 0.2 |
| Disease duration | 25 (23.5–26.5) | 22 (9.75–30.25) | 23 (20–28.5) | 0.77 |
| MFMD1 | 13 (11–14.25) | 19 (16–20) | 22 (20–24.5) | < 0.0001 |
| 6MWT | 242 (237–306) | 352 (286–386) | 420 (388–446) | < 0.0001 |
| 4-Stair climb score (* n=42) | ||||
| 2 | 5 (100) | 6 (28.57) | 2 (11.76) | 0.001 |
| 5 | 0 (0) | 15 (71.43) | 13 (76.47) | |
| 6 | 0 (0) | 0 (0) | 2 (11.76) | |
| 10 m score | 0.21 | |||
| 3 | 1 (16.67) | 2 (9.09) | 0 (0) | |
| 4 | 5 (83.33) | 19 (86.36) | 12 (70.59) | |
| 5 | 0 (0) | 1 (4.55) | 3 (17.65) | |
| 6 | 0 (0) | 0 (0) | 2 (11.76) | |
| Gowers Score (* n=38) | 0.17 | |||
| 1 | 2 (50) | 1 (5.56) | 0 (0) | |
| 2 | 2 (50) | 13 (72.22) | 8 (47.06) | |
| 3 | 0 (0) | 2 (11.11) | 3 (17.65) | |
| 4 | 0 (0) | 2 (11.11) | 4 (23.53) | |
| 5 | 0 (0) | 0 (0) | 1 (5.88) | |
| 6 | 0 (0) | 0 (0) | 1 (5.88) | |
| Right Biceps Brachial Strength | 12.67 (7.75–34.58) | 53.17 (34.50–73.67) | 141.3 (91.33–160.7) | < 0.0001 |
| Left Biceps Brachial Strength | 15 (7.08–40.25) | 59.33 (36–75.5) | 135 (107–155.8) | < 0.0001 |
| Nuclear Centralizations | 4 (2–5) | 5 (3–7) | 4 (3–5) | 0.25 |
| MFA % | 34.18 (10.73–52.82) | 72.55 (60.89–79.86) | 82.59 (79.96–88.25) | < 0.0001 |
| Fibrotic tissue % | 53.05 (36.79–84.78) | 25.40 (19.69–36.06) | 15.90 (11.57–18.97) | < 0.0001 |
| Fatty tissue % | 7.22 (2.12–13.49) | 0 (0–0) | 0 (0–0) | < 0.0001 |
| Other tissue % | 0.34 (0–3.14) | 0 (0–0) | 0 (0–0.25) | 0.12 |
| CSA I | 3007 (1711–4780) | 3334 (2250–6006) | 5234 (4023–6390) | 0.07 |
| CSA I Fibre size variability | 4667 (3519–5254) | 2668 (2018–4596) | 3691 (2509–4651) | 0.17 |
| CSA II | 2382 (1093–3042) | 3555 (1720–4776) | 5769 (5044–7574) | < 0.0001 |
| CSA II Fibre size variability | 3868 (1528–4550) | 4422 (3162–6079) | 4726 (4067–7309) | 0.17 |
| Regenerating fibres % | 0.61 (0.12–12.94) | 4.18 (0–7.34) | 3.4 (0.3–6.11) | 0.88 |
| Splitting fibres% | 2.17 (0–4.17) | 4.6 (2.27–6.71) | 1.84 (0.83–5.5) | 0.07 |
| Necrosis fibres% | 1.45 (0.66–1.61) | 0.81 (0–2.19) | 0 (0–1.09) | 0.12 |
Statistically significant p values are shown in bold
Data are expressed as median (25th-75th percentiles) and number (frequencies), as appropriate. Statistics computed by Kruskal Wallis Test, except for categorical variables (Fisher’s exact test)
BMI: Body Mass Index; MFMD Motor Function Measure Domain; 6MWT: 6 Minute Walking Test; 10mScore: 10 m score; MFA: muscle fibre area; CSA: cross sectional area