Respiratory features of neuromuscular diseases
| Condition | Respiratory failure | Secretion clearance difficulty | Recurrent pneumonia | Progression | Disease-specific features |
| SMA | |||||
| Type 1 | All by 2 years | Marked | All | Rapid | All require full-time respiratory support |
| Type 2 | ∼40% in childhood | Early | ∼25% in first 5 years | Slow | |
| Type 3 | Rare in childhood | Rare in childhood | Rare in childhood | Slow | |
| SMA with respiratory distress type 1 | All by 6 months | Marked | All | Rapid in first year, then slows. | All require full-time respiratory support |
| DMD/severe childhood onset limb-girdle muscular dystrophy | After loss of ambulation | After loss of ambulation | Late | Cardiomyopathy usually occurs after respiratory problems but may precede them | |
| Facioscapulohumeral muscular dystrophy | When onset <20 years | With infantile onset | With infantile onset | Slow | Severe infantile onset type is frequently associated with sensorineural deafness |
| Congenital muscular dystrophy | |||||
| All types | Any age depending on severity | Any age depending on severity | Any age depending on severity | Slow | |
| Ullrich | 70% in adolescence | Mild | Infrequent | Proximal contractures with marked distal laxity | |
| Rigid spine muscular dystrophy | Early while ambulation preserved | Mild | Infrequent | Hypoventilation may occur in ambulant children with relatively preserved vital capacity | |
| Congenital myopathy | |||||
| Central core | Uncommon except in severe recessive type | Uncommon | Uncommon | Slow | Susceptible to malignant hyperthermia |
| Minicore | Early while ambulation preserved | ||||
| Nemaline | Early in severe neonatal form, mild later onset form may develop early while ambulation preserved | In severe form | In severe form | Slow | |
| Myotubular | 85% in severe X-linked form | In severe form | In severe form | Slow | Ophthalmoplegia, rare coagulopathy and liver haemorrhage |
| Fibre type disproportion | Depends on genotype | Uncommon | Uncommon | ||
| Myotonic dystrophy | |||||
| Myotonic dystrophy 1 | Common in severe congenital onset, usually improves | Common in severe congenital onset | Common in severe congenital onset | Initial improvement, later slow deterioration | Prominent learning difficulty, somnolence, central hypoventilation |
| Myotonic dystrophy 2 | Uncommon | Uncommon | Uncommon | ||
| Congenital myasthenic syndromes | Often in neonatal period, may occur during inter-current illnesses | Especially during inter-current illnesses | Possible if weakness severe and persistent | Weakness may fluctuate, episodic apnoea in some. Congenital stridor in those with DOK7 mutations | |
| Mitochondrial myopathy | Common | Possible | Possible | Acute deterioration possible | |
| Charcot–Marie–Tooth | With severe early onset, especially with GDAP1 mutation | With severe early onset | With severe early onset | Stridor, especially with GDAP1 mutation | |
| Pompe | Infantile onset, may be early in later onset while ambulation preserved | Infantile onset | Infantile onset | Infantile rapid, late onset slow | Variable relationship between motor and respiratory progression |
DMD, Duchenne muscular dystrophy; SMA, spinal muscular atrophy.