Table 1.
Clinical Details of Cases with DPAGT1 Mutations
| Case 1 | Case 2 | Case 3 | Case 4 | Case 5 | |
|---|---|---|---|---|---|
| Gender | male | female | male | female | female |
| Current age | 43 years | 57 years | 25 years | 58 years | 6 years |
| Age when assessed | 43 years | 53 years | 17 years | 48 years | 6 years |
| Mutations | c.324G>C (p.Met108Ile) and c.349G>A (p.Val117Ile) | c.349G>A (p.Val117Ile) and c.699dup (p.Thr234Hisfs∗116) | c.358C>A (p.Leu120Met) and c.791T>G (p.Val264Gly) | c.478G>A (p.Gly160Ser) and c.574G>A (p.Gly192Ser) | c.358C>A (p.Leu120Met) and c.791T>G (p.Val264Gly) |
| Progression | stable but with long-term fluctuations | slowly progressive | some improvement during teenage years | slowly progressive | stable in infancy and small improvement in childhood |
| Age of onset | 2.5 years | 7 years | 0.5 years | 2 years | in first year |
| Symptoms at onset | episodic difficulty walking | falls and is unable to keep up with friends | hypotonia and poor head control | abnormal gait | hypotonia and delayed motor development |
| Ptosis | − | − | + (mild and fatigable) | − | − |
| Ophthalmoplegia | − | − | − | − | − |
| Wasting | − | − | − (although thin) | sternocleidomastoid | − |
| Contractures | − | − | − | − | − |
| Spine | − | scoliosis | scoliosis | − | − |
| Decrement on RNS | + | + | + | + | + |
| Muscle biopsy | tubular aggregates | tubular aggregates | tubular aggregates | tubular aggregates | ND |
| Positive response to treatment | P, D, Sa | P, D | P | P, D | P |
| MRC Muscle Power Grade | |||||
| Face | 5 | 5− | 5 | 5 | 5− |
| Neck flexion/extension | 5/4 | 4+/4+ | 4/5 | 4/5 | 4/4 |
| Shoulder abduction | 4− | 3− | 4− | 3 | 4 |
| Elbow flexion/extension | 4−/4− | 4/4 | 4+/4− | 4+/3+ | 4/4 |
| Wrist/finger extension | 4−/ND | 4+/4+ | 5/4 | ND/ND | 5−/5− |
| Finger/thumb abduction | 4/ND | 4+/4+ | 4/ND | ND/ND | 5/5 |
| Hip flexion/extension | 4/4+ | 4/4+ | 4−/ND | 4−/ND | 4+/4+ |
| Knee flexion/extension | 4+/4 | 4+/4+ | 4+/4 | 4/4 | 4+/4+ |
| Ankle dorsiflexion | 4− | 4+ | 4 | 4 | 5− |
| Single-Fiber Electromyography | |||||
| Abnormal jitter | + | + | + | + | ND |
| Blocking | + | + | + | + | ND |
Bold text indicates ongoing treatment. The following abbreviations are used: ND, not done; RNS, repetitive nerve stimulation; P, pyridostigmine; D, 3, 4-diaminopyridine; Sa, Salbutamol; and MRC, Medical Research Council.