Table 1.

Clinical characteristics and pulmonary function parameters of the sibs (Patient III:1, III:2, III:3)

Characteristic (age of onset, years)	Patients
	III:1	III:2	III:3
Beginning of independent walking	3–4	3	2.5
Running and jumping	Impossible	Impossible	Delay
Muscular weakness	3 (m. quadr.	3 (m. quadr.	6–7 (m. quadr.
	femor. 3/5 MRC)	femor. 3–4/5 MRC)	femor. 4/5 MRC)
Difficulty in stair climbing	3–4	3–4	33
Difficulty in standing up from a sitting position	6	7	40
Means of support	7–13 (crutches)	10–13 (crutches)	Did not use
Muscle atrophy	Shoulder girdle,	Diffuse, shoulder	Shoulder girdle and
	upper limbs	girdle mainly	upper limbs
Knee joint contractures	3–4	3–4	7–8
Hip joints contractures	3–4	3–4	7–8
Elbow joint contractures	13–14	13	18–19
Shoulder joint contractures	16–18	15–16	23–25
Wrist joint contractures	23–25	18	30–32
Achilles tendon contractures	13	13	16–17
Joint hypermobility	Does not persist	Persists	Persists
Dyspnea, years	No	40	40
Pulmonary function parameters (at the last visit)
Age at last visit, y.o.	48	53	58
Tidal volume, ml (Δ% of N)	200 (50)	100 (25)	150 (37.5)
VC, ml (Δ%, of proper VC)	1400 (39.2)	1100 (33.8)	1800 (52.3)
Proper VC, ml.	3572	3252	3444
Inspiratory reserve volume, ml (Δ% of N)	800 (57)	700 (50)	1000 (71)
Expiratory reserve volume, ml (Δ% of N)	400 (40)	300 (30)	650 (65)

Note: 1. VC is the vital capacity of the lungs; 2. Proper VC of the lungs = height (cm)×0.052 –age (years)×0.028 –3.2; 3. N expiratory reserve volume (ERV) –1000–1400 ml; 4. N inspiratory reserve volume (IRV) –1400 ml (IRV = VC –(RV + ERV)).