Table 1 Clinical, neuroradiological and molecular findings of the patients
Fam/Pt ID | Age at onset | Age at last evaluation | Clinical symptoms at onset | Developmental delay/ Mental retardation | Neurological findings | Peripheral neuropathy | Clinical severity score# | Brain MRI findings | Molecular findings | |
|---|---|---|---|---|---|---|---|---|---|---|
|  |  |  |  |  |  |  |  |  | Genotype | Nature of mutation ♣ |
1 | Birth | 8 y | Nystagmus Muscular hypotonia | Severe MR | Axial hypotonia Limb spasticity Pyramidal signs | + | 0 | Hypo (Supra/Infra) | c.453G>T (p.Lys151Asn)â™ | Inherited |
2 | Birth | 5 m | Nystagmus Stridor | + | Spastic tetraparesis | Absent | 0 | Hypo | c.552C>G (p.Cys184Trp) | Inherited |
3 | Birth | 4 y | Nystagmus Muscular hypotonia | + | Muscular hypotonia | NT | 0 | Hypo (Supra/Infra) | c.689C>T (p.Thr230Ile) | Inherited |
4 | Birth | 12 y | Nystagmus Muscular hypotonia | Severe MR | Muscular hypotonia Pyramidal signs | Absent | 1 | Hypo (Supra/Infra) | c.89C>A (p.Ala30Glu) | Inherited |
5 | 2 m | 2 y | Nystagmus | + | Spastic tetraparesis | Absent | 1 | Hypo (Supra/Infra) | c.505T>C (p.Cys169Arg) | Inherited |
6 | Birth | 3 y | Nystagmus Muscular hypotonia | Mild MR | Muscular hypotonia Pyramidal signs | Absent* | 1 | Hypo | c.554_564del11 â™ (p.Gln185LeufsX15) | Inherited |
7 | Birth | 18 y | Nystagmus Muscular hypotonia | Severe MR | Muscular hypotonia Pyramidal signs | Absent | 1 | Hypo | c.634T>C | Inherited |
| Â | Birth | 2 y | Nystagmus Muscular hypotonia | Mild MR | Muscular hypotonia Pyramidal signs | Absent | 1 | Hypo | (p.Trp212Arg) | Â |
8 | 3 m | 4 y | Nystagmus Muscular hypotonia | Mild MR | Spastic tetraparesis | + | 2 | Hypo (Supra/Infra) | c.205C>T (p.Gln69X)â™ | Inherited |
9 | 8 m | 9 y | Nystagmus Developmental delay | Mild MR | Spastic tetraparesis | + | 3 | Hypo | c.1-329_c.1_c.4 +324del657â™ | Inherited |
10 | 4 m | 14 y | Nystagmus Muscular hypotonia | + | Spastic tetraparesis | + | 3 | Hypo (Supra/Infra) | c.134_140dup7 (p.Ile47IlefsX4)â™ | Inherited |
11 | 6 m | 30 y | Nystagmus | - | Limb spasticity Poor tendon reflexes | NT | 4 | NT | c.436C>G (p.Leu146Val)â™ | Inherited |
12 | Birth | 11 m | Nystagmus Stridor | + | Muscular hypotonia | NT | ♦ | Hypo | c.83G>T (p.Gly28Val) | Inherited |
13 | Birth | 11 m | Nystagmus | Mild MR | Muscular hypotonia | Absent | ♦ | Hypo (Supra/Infra) | c.476T>C (p.Leu159Pro) | De novo |
14 | 1 m | 3 m | Nystagmus Muscular hypotonia | + | Muscular hypotonia | NT | ♦ | Hypo | c.740C>A (p.Ala247Asp) | Inherited |
15 | Birth | 5 y | Nystagmus Muscular hypotonia | Severe MR | Muscular hypotonia Pyramidal signs | Absent | 0 | Hypo (Supra/Infra) | PLP1 dup | NA |
16 | Birth | 18 m | Nystagmus Muscular hypotonia Stridor | Mild MR | Muscular hypotonia | Absent | 0 | Hypo (Supra/Infra) | PLP1 dup | De novo |
17 | 1 m | 17 y | Nystagmus | Mild MR | Muscular hypotonia | Absent | 1 | Hypo (Supra/Infra) | PLP1 dup | NA |
18 | 3 m | 10 y | Nystagmus Muscular hypotonia | + | Muscular hypotonia Pyramidal signs Dystonia Ataxia | Absent | 1 | Hypo | PLP1 dup | Inherited |
| Â | 2 m | 11 y | Nystagmus Muscular hypotonia | Moderate MR | Spastic tetraparesis Dystonia | Absent | 1 | Hypo | Â | Â |
19 | 1 m | 2 y | Nystagmus | Moderate MR | Muscular hypotonia Pyramidal signs Dystonia | Absent | 1 | Hypo (Supra/Infra) | PLP1 dup | Inherited |
20 | 1 m | 4 y | Nystagmus | Mild MR | Muscular hypotonia Pyramidal signs | Absent | 2 | Hypo | PLP1 dup | Inherited |
21 | 2 m | 4 y | Nystagmus | + | Muscular hypotonia | Absent | 2 | Hypo | PLP1 dup | NA |
22 | 2 m | 4 m | Nystagmus Muscular hypotonia | Mild MR | Muscular hypotonia | Absent | 2 | Hypo | PLP1 dup | NA |
23 | 4 m | 2 y | Nystagmus | Mild MR | Muscular hypotonia | Absent | 2 | Hypo | PLP1 dup | Inherited |
24 | Birth | 22 y | Nystagmus | Severe MR | Spastic tetraparesis Dystonia | Absent | 2 | Hypo | PLP1 dup | Inherited |
25 | 8 m | 2 y | Nystagmus Developmental delay | + | Spastic tetraparesis | Absent | 2 | Hypo | PLP1 dup | Inherited |
26 | 1 m | 4 y | Nystagmus | Severe MR | Pyramidal signs Dystonia | Absent | 2 | Hypo | PLP1 dup | Inherited |
27 | 5 m | 2 y | Nystagmus | Severe MR | Muscular hypotonia | Absent | 2 | Hypo | PLP1 dup | De novo |
| Â | 15 d | 5 y | Nystagmus Seizures | Moderate MR | Spastic tetraparesis Dystonia | Absent | 2 | Hypo | Â | Â |
28 | 1 m | 8 y | Nystagmus | + | Pyramidal signs Dystonia | Absent | 2 | Hypo | PLP1 dup | Inherited |
| Â | 4 m | 29 y | Nystagmus Seizures | + | Pyramidal signs Dystonia | Absent | 3 | Hypo | Â | Â |
29 | 1 y | 25 y | Nystagmus Developmental delay | Severe MR | Spastic tetraparesis | Absent | 3 | Hypo | PLP1 dup | Inherited |
| Â | 1 y | 23 y | Nystagmus Developmental delay | Severe MR | Spastic tetraparesis | Absent | 3 | Hypo | Â | Â |
30 | 3 m | 5 y | Nystagmus | Mild MR | Muscular hypotonia Pyramidal signs | Absent | 3 | Hypo (Supra/Infra) | PLP1 dup | Inherited |
31 | Birth | 3 m | Nystagmus Muscular hypotonia | Mild MR | Muscular hypotonia | Absent | 3 | Hypo | PLP1 dup | NA |
32 | 2 m | 6 y | Nystagmus | Moderate MR | Pyramidal signs Ataxia | Absent | 3 | Hypo | PLP1 dup | Inherited |
33 | 6 y | 30 y | Nystagmus Learning difficulties Behavioural problems | Moderate MR | Limb spasticity Ataxia | Absent | 4 | Hypo | PLP1 dup | NA |
34 | 3 m | 11 m | Nystagmus Muscular hypotonia | + | Muscular hypotonia Pyramidal signs | Absent | ♦ | Hypo (Supra/Infra) | PLP1 dup | Inherited |
35 | 1 m | 7 m | Nystagmus | + | Muscular hypotonia | Absent | ♦ | Hypo | PLP1 dup | NA |
36 | 3 m | 11 m | Nystagmus Muscular hypotonia | + | Muscular hypotonia Dystonia | Absent | ♦ | Hypo | PLP1 dup | NA |
37 | 1 m | 11m | Nystagmus | + | Muscular hypotonia | Absent | ♦ | Hypo | PLP1 dup | De novo |
38 | 3 m | 8 m | Nystagmus Muscular hypotonia | + | Muscular hypotonia | Absent | ♦ | Hypo (Supra/Infra) | PLP1 dup | NA |