Table 2.
Patient and mutation data were obtained from the European Skeletal Dysplasia Network (ESDN reference numbers) or recent publications, as referenced.
| Reference | Features | Diagnosis | Gene | Mutation | Effect |
|---|---|---|---|---|---|
| ESDN 01071 | – Fatigue during walking | MED | MATN3 | D176V | Potential misfolding |
| – Muscle disease suspected by paediatrician | |||||
| ESDN 01013 | – Mild proximal muscle weakness at 7 years | MED | COL9A2 | c186G > C | Exon skipping |
| – Difficulty rising from squatting position | |||||
| ESDN 01003 | – Mild muscle weakness | MED | COL9A2 | c186 + 4a > c | Exon skipping |
| [68] | – Muscle weakness | MED | COL9A2 | c186 + 2t > c | Exon skipping |
| – Suspected (unproven) muscular dystrophy | |||||
| – Problems with standing up from sitting position | |||||
| – Problems walking on stairs | |||||
| – Biopsy: | |||||
| – No morphological or histochemical changes | |||||
| – No fibers with central nuclei | |||||
| – Variation in fiber size | |||||
| – No degradation, regeneration, or necrosis | |||||
| – ATP + CrP production from pyruvate | |||||
| decreased | |||||
| [68] | – Neurological evaluation for abnormal walking | MED | COL9A2 | c186G > A | Exon skipping |
| pattern at 6 years | |||||
| – Proximal muscle weakness lower extremities | |||||
| – Family also affected (father, sister, sister's | |||||
| daughter) | |||||
| [54] | – Proximal muscle weakness (reported to the | MED | COL9A3 | IVS2-1, G > A | Exon skipping |
| neuromuscular clinic at 10 years) | |||||
| – Mildly elevated serum creatine kinase (CK) | |||||
| levels | |||||
| – Difficulty walking and climbing stairs from 3 | |||||
| years on | |||||
| – Difficulty rising from the floor | |||||
| – Some signs of proximal muscle weakness in | |||||
| family members | |||||
| – Muscle biopsy: mild variability in fibre size | |||||
| ESDN 00385 | – Some signs of mild myopathy | PSACH | COMP | D326Y | Potential retention (T3 domain mutation) |
| – Gower's sign (proximal muscle weakness) | |||||
| – Waddling gait | |||||
| – Difficulties climbing stairs | |||||
| – CPK normal | |||||
| ESDN 00430 | – Reported to neurologist at age 2 | MED | COMP | E457del | Potential retention (T3 domain mutation) |
| – Diminished muscle strength in: | |||||
| – Hips | |||||
| – Shoulders | |||||
| – Quadriceps muscle | |||||
| – Feet-lifting muscles | |||||
| – Diagnosed with a myopathy at 5 years | |||||
| – Biopsy inconclusive | |||||
| [55] | – Difficulty walking at 2.5 years | MED | COMP | D605N | Potential misfolding (CTD mutation) |
| – Muscle weakness | |||||
| – Tired easily | |||||
| – Difficulty getting up from sitting | |||||
| – CK levels normal | |||||
| – EMG and nerve conduction velocities normal | |||||
| – Biopsy: | |||||
| – Mild myopathy, | |||||
| – No variability in fibre size | |||||
| – Scattered basophilic fibers | |||||
| – Some small atrophic fibers | |||||
| [53, 55] | – Muscle weakness from 3 years on | MED | COMP | R718W | Potential misfolding (CTD mutation) |
| – Referred to neuromuscular clinic at 5 years | |||||
| – Mildly elevated CK levels | |||||