Table 2. Analysis of cases by disease group.
| Disease group | No. of cases based on clinical diagnosis | No.of cases confirmed according to diagnostic standard (Table 1) | Proportion (%) of clinic population affected (with 95% confidence intervals) | Estimated point prevalence per 100 000 (with 95% confidence intervals) |
|---|---|---|---|---|
| Muscular dystrophies | ||||
| Duchenne (DMD) | 124 | 124 | 11.2 (9.4–13.1) | 8.29a (6.8–9.8) |
| Intermediate (IMD) | 7 | 7 | 0.6 (0.2–1.1) | 0.47a (0.1–0.8) |
| Becker (BMD) | 109 | 109 | 9.9 (8.1–11.6) | 7.29a (5.9–8.7) |
| Manifesting carriers | 13 | 13 | 1.2 (0.5–1.8) | 0.43 (0.2–0.7) |
| Total | 253 | 253 | 22.9 (20.4–25.4) | 8.46 (7.4–9.5) |
| Facioscapulohumeral muscular dystrophy (FSHD) | 118 | 116 | 10.7 (8.9–12.5) | 3.95 (3.2–4.7) |
| LGMD1B (AD EDMD) | 6 | 6 | 8.8b (2.1–15.6) | 0.20 (0–0.4) |
| LGMD2A | 18 | 15 | 26.5b (16.0–37.0) | 0.60 (0.3–0.9) |
| LGMD2B | 4 | 2 | 5.9b (0.3–11.5) | 0.13 (0–0.3) |
| LGMD2C | 4 | 4 | 5.9b (0.3–11.5) | 0.13 (0–0.3) |
| LGMD2D | 2 | 2 | 2.9b (0–7.0) | 0.07 (0–0.2) |
| LGMD2E | 2 | 2 | 2.9b (0–7.0) | 0.07 (0–0.2) |
| LGMD2I | 13 | 12 | 19.1b (9.8–28.5) | 0.43 (0.2–0.7) |
| LGMD unconfirmed | 19 | NA | 27.9b (17.3–38.6) | 0.64 (0.4–0.9) |
| Total LGMD | 68 | 43 | 6.15 (4.7–7.6) | 2.27 (1.7–2.8) |
| Emery–Dreifuss muscular dystrophy X-linked (EDMD-X) | 4 | 4 | 0.36 (0–0.7) | 0.13 (0–0.3) |
| Oculopharyngeal muscular dystrophy | 4 | 4 | 0.36 (0–0.7) | 0.13 (0–0.3) |
| CMD | ||||
| MDC1A | 18 | 18 | 1.62 (0.9–2.4) | 0.60 (0.3–0.9) |
| Walker–Warburg syndrome | 1 | 1 (POMGnT1) | 0.09 (0–0.3) | 0.03 (0.01) |
| UCMD | 4 | 3 | 0.36 (0–0.7) | 0.13 (0–0.3) |
| RSMD | 4 | 1 | 0.36 (0–0.7) | 0.13 (0–0.3) |
| Congenital myopathies | ||||
| Nemaline myopathy | 6 | 5 | 0.54 (0.1–1.0) | 0.20 (0–0.4) |
| Bethlem myopathy | 23 | 18 | 2.08 (1.2–2.9) | 0.77 (0.5–1.1) |
| Central core disease | 12 | 10 | 1.09 (0.5–1.7) | 0.40 (0.2–0.6) |
| Distal myopathy | 10 | 0 | 0.90 (0.4–1.5) | 0.33 (0.1–0.5) |
| Myofibrillar myopathy | 7 | 2 (MYOT) | 0.18 (0–0.4) | 0.07 (0–0.2) |
| 5 (DES) | 0.45 (0.1–0.9) | 0.17 (0–0.3) | ||
| Myotonic dystrophies | ||||
| DM1 | 311 | 311 | 28.1 (25.5–30.9) | 10.4 (9.3–11.6) |
| DM2 | 5 | 5 | 0.45 (0.1–0.9) | 0.17 |
| Spinal muscular atrophies | ||||
| MA type I | 3 | 3 | 0.27 (0–0.6) | 0.10 (0–0.2) |
| SMA type II | 17 | 17 | 1.54 (0.8–2.3) | 0.57 (0.3–0.8) |
| SMA type III | 36 | 19 | 1.72 (1.0–2.5) | 0.64 (0.4–0.9) |
| 17 inconclusive | 1.54 (0.8–2.3) | 0.57 (0.3–0.8) | ||
| Total | 56 | 39 | 5.07 (3.8–6.4) | 1.87 (1.4–2.4) |
| Others | ||||
| Excluded categories (e.g. HMSN etc.) | 5 | NA | 5.25 (3.9–6.6) | 1.94 (1.4–2.4) |
| Uncertain diagnosis/tests in progress | 145 | NA | 13.1 (11.1–15.1) | NA |
| Patients with confirmed diagnosis | NA | 836 | 75.7 (73.1–78.2) | NA |
| Total number of patients in database | 1105 | NA | NA | 37.0 |
The table lists the number of cases in each disease group category and those confirmed to the diagnostic standard listed in Table 1. It shows the proportion of our clinic population affected by each condition and the estimated population prevalence for each condition.
a
Males only.
b
Proportion of total LGMD patients.
RSMD = CMD with rigidity of the spine; HMSN = hereditary motor and sensory neuropathies.