Evidence map›Paper›PMID 34996390›Full record

ArticleBMC neurology2022

Coexistence of Charcot-Marie-Tooth 1A and nondystrophic myotonia due to PMP22 duplication and SCN4A pathogenic variants: a case report.

Haitian Nan, Yunqing Wu, Shilei Cui, Houliang Sun, Jiawei Wang, Ying Li, Lingchao Meng, Takamura Nagasaka, Liyong Wu

Open access · goldAbstract readCase Reports
In one paragraph

Article in BMC neurology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed, 1 pooled it
0.1field-weighted citation impact, top 66% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed, 1 synthesis or guideline pooled it, 1 citations in OpenAlex.

  1. Genes · 2025
    Pooled it
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors at 4 institutions in 2 countries.

Haitian Nan *Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Yunqing Wu *Department of Neurology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Shilei CuiDepartment of Neurology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Houliang SunDepartment of Neurology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Jiawei WangDepartment of Neurology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Ying LiDepartment of Neurology, Peking University First Hospital, Beijing, China.
Lingchao MengDepartment of Neurology, Peking University First Hospital, Beijing, China.
Takamura NagasakaDepartment of Neurology, University of Yamanashi, 1110 Shimokato, Chuo-city, Yamanashi, 409-3898, Japan.
Liyong WuDepartment of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China. wmywly@hotmail.com.ORCID http://orcid.org/0000-0002-1251-6130
Beijing Tongren Hospital · CNCapital Medical University · CNPeking University · CNUniversity of Yamanashi Hospital · JP

Funding

Ministry of Science and Technology of the People's Republic of China 2019YFC0118600National Natural Science Foundation of China 81971011
6 · The paper itself

Abstract

backgroundCharcot-Marie-Tooth disease (CMT) is a genetically heterogeneous hereditary neuropathy, and CMT1A is the most common form; it is caused by a duplication of the peripheral myelin protein 22 (PMP22) gene. Mutations in the transient sodium channel Nav1.4 alpha subunit (SCN4A) gene underlie a diverse group of dominantly inherited nondystrophic myotonias that run the spectrum from subclinical myopathy to severe muscle stiffness, disabling weakness, or frank episodes of paralysis. CASE PRESENTATION: We describe a Chinese family affected by both CMT1A and myotonia with concomitant alterations in both the PMP22 and SCN4A genes. In this family, the affected proband inherited the disease from his father in an autosomal dominant manner. Genetic analysis confirmed duplication of the PMP22 gene and a missense c.3917G > C (p. Gly1306Ala) mutation in SCN4A in both the proband and his father. The clinical phenotype in the proband showed the combined involvement of skeletal muscle and peripheral nerves. Electromyography showed myopathic changes, including myotonic discharges. MRI revealed the concurrence of neurogenic and myogenic changes in the lower leg muscles. Sural nerve biopsies revealed a chronic demyelinating and remyelinating process with onion bulb formations in the proband. The proband's father presented with confirmed subclinical myopathy, very mild distal atrophy and proximal hypertrophy of the lower leg muscles, pes cavus, and areflexia.

conclusionThis study reports the coexistence of PMP22 duplication and SCN4A mutation. The presenting features in this family suggested that both neuropathy and myopathy were inherited in an autosomal dominant manner. The proband had a typical phenotype of sodium channel myotonia (SCM) and CMT1A. However, his father with the same mutations presented a much milder clinical phenotype. Our study might expand the genetic and phenotypic spectra of neuromuscular disorders with concomitant mutations.

Indexed as

ArthrogryposisCharcot-Marie-Tooth DiseaseMyotoniaHumansMaleMyelin ProteinsNAV1.4 Voltage-Gated Sodium ChannelProteinsMyelin ProteinsNAV1.4 Voltage-Gated Sodium ChannelPMP22 protein, humanProteinsSCN4A protein, humanCase reportCharcot-Marie-Tooth diseaseNondystrophic myotoniaPMP22SCN4A

Identifiers

PMID34996390
PMCPMC8740465
OpenAlexW4205949551

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