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| Author | Year | Study design | Number of subjects | T118M genotype | Findings | Supported modality of disease |
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| Roa et al. [2] | 1993 | Case series | 1 family | Heterozygote | One patient heterozygous for T118M did not show symptoms. One patient hemizygous for both T118M and 1.5-Mb deletion had severe neuropathy. | Benign polymorphism |
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| Nelis et al. [12] | 1994 | Case series | 2 families | Heterozygote | One patient heterozygous for T118M showed CMT1 symptoms, but father showed no symptoms despite having the variant. Another patient with T118M variant in another CMT1 family showed no symptoms. | Benign polymorphism |
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| Mersiyanova et al. [13] | 2000 | Mutation screen of CMT and HNPP patients. | 174 unrelated CMT patients and 3 HNPP families | Heterozygote | Unclear which patient(s) had the T118M variant. | Unclear |
|
| Young et al. [11] | 2000 | Case control | 1018 healthy, 104 with HNPP, 187 with CMT1 with 1.5-Mb duplication, 22 with CMT1 phenotype without PMP22 mutations. | Heterozygote | Minor allele frequency lower in general population (AF=0.007) compared to HNPP cases (AF= 0.01), CMT1 with 1.5Mb duplication (AF=0.016) and CMT1 without duplication (AF=0.05). T118M was associated with CMT1A without the 1.5-Mb duplication (P=0.0429), but not with HNPP or CMT1 due to the low allele frequency. | Supports the association of T118M with CMT1A in the absence of the PMP22 duplication. |
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| Marques et al. [9] | 2003 | Case series | 1 family | Heterozygote | Three patients with CMT1 were genotyped. Two had both the 17p11.2-p12 duplication and the T118M variant, while one had only the duplication. Phenotype only available in proband (T118M + duplication). Unclear whether T118M worsened phenotype. | Unclear |
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| Seeman et al. [10] | 2006 | Case series | 1 family | Heterozygote | Two asymptomatic patients had T118M variant, one patient had both the T118M variant and the 17p11.2-12 duplication and had CMT1 phenotype. | Benign polymorphism |
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| Shy et al. [8] | 2006 | Case series | 5 unrelated kindreds | 3 with T118M/normal, 2 with T118/deletion, 1 with (T118+duplication)/normal, 2 1 with T118M/T118M | T118M/deletion had severe demyelinating phenotype, T118M/T118M had severe axonal phenotype, T118M/normal had mild HNPP phenotype, (T118M + duplication)/normal had mild demyelinating phenotype | Partial loss of function |
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| Jerath et al. [14] | 2015 | Case report | 1 case | T118M/17p11.2-p12 deletion | Severe sensorimotor polyneuropathy | Benign polymorphism vs partial loss of function |
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| This study | 2018 | Case series | 3 unrelated cases | Heterozygote | All three had painful polyneuropathy. 1 had moderate sensorimotor polyneuropathy with both axonal and demyelinating features, 2 had mildly decreased conduction velocity. | Partial loss of function – can cause painful polyneuropathy |
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