Table 2.
Main phenotype data in all Spanish McArdle patients (n = 333)
| N with data | Result (men + women) | Main change with regards to previous data (n = 239 patients) [1] | |
|---|---|---|---|
| Gender | 55% male | ↔ | |
| Age, years (mean ± SD, range) |
333 | 48 ± 19 (12, 99)a | ↑ |
| BMI, kg/m2
(mean ± SD, range) |
132 | 24.7 ± 4.8 (16, 43) | ↔ |
| Familial consaguinity (%) | 188 | 17% | ↑ |
| Symptomatic father (%)a | 201 | 3% | ↔ |
| Symptomatic mother (%)a | 201 | 6% | ↔ |
| Symptoms’ onset (%) | 235 | ||
| 1st decade | 66% | ↑ | |
| 2nd decade | 20% | ↓ | |
| 3rd decade | 5% | ↔ | |
| ≥4th decade | 9% | ↔ | |
| Genetic diagnosis (%) | 275 | ||
| 1st decade | 5% | ↔ | |
| 2nd decade | 23% | ↔ | |
| 3rd decade | 23% | ↔ | |
| ≥4th decade | 49% | ↔ | |
| Exercise intolerance (%) | 272 | 99.6% | ↔ |
| Second wind, self-reported (%) | 164 | 91.5% | ↑ |
| Second wind, laboratory- determined (%) | 119 | 99.2% | ↔ |
| Fixed muscle weakness (%) | 240 | 21% | ↓ |
| Recurrent episodes of myoglobinuria (%) | 240 | 51% | ↔ |
| Disease severity (%)b | 240 | ||
| Class 0 | 8% | ↔ | |
| Class 1 | 41% | ↔ | |
| Class 2 | 30% | ↑ | |
| Class 3 | 21% | ↓ | |
| Disease progression (%) | 151 | ||
| Improvement | 34% | ↑↑ | |
| Worsening | 28% | ↔ | |
| Constant | 35% | ↓↓ | |
| Acute renal failure (%) | 173 | 6% | ↔ |
| Chronic renal failure (%) | 171 | 1% | ↔ |
| Comorbidities (%) | |||
| Diabetesc | 140 | 9% | ↔ |
| CAD | 136 | 9% | ↔ |
| Hypertension | 135 | 11% | ↔ |
| Cancer | 134 | 1% | ↔ |
| Obesity | 127 | 10% | ↔ |
| COPD | 131 | 1% | ↔ |
| Serum CK (%) >200 U/L, >1000 U/L | 179 | 98%, 68% | ↔, ↓ |
| Biopsy diagnosis (%) | 205 | 100% | ↔ |
| Physical activity data (% active) | 120 | 50% | ↑↑ |
| VO2peak, mLO2/kg/min (mean ± SD, range) | 120 | 19.9 ± 6.6 (5.9, 41.5) | ↔ |
Data on 3 patients (all males) who died recently (all after the 6th decade of life, due to cardiovascular disease) are included
Symbols: a ‘symptomatic’ refers to having the main symptomatic features of McArdle disease (i.e., exercise intolerance with or without myoglobinuria or self-reported second wind)
bdisease severity class following the classification originally reported by Martinuzzi et al. [2]: 0 = asymptomatic or virtually asymptomatic (mild exercise intolerance, but no functional limitation in any daily life activity); 1 = exercise intolerance, contractures, myalgia, and limitation of acute strenuous exercise, and occasionally in daily life activities; no record of myoglobinuria, no muscle wasting or weakness; 2 = same as 1, plus recurrent exertional myoglobinuria, moderate restriction in exercise, and limitation in daily life activities; 3 = same as 2, plus fixed muscle weakness, with or without wasting and severe limitations on exercise and most daily life activities
cdiabetes diagnosed based on a glucose tolerance test. Abbreviations: BMI, body mass index; CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; VO2peak, peak oxygen uptake