Genotypic and phenotypic features of all Spanish patients with McArdle disease: a 2016 update

BMC Genomics

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 (%)
Diabetes^c	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

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