Charcot-Marie-Tooth type 2CC misdiagnosed as Chronic Inflammatory Demyelinating Polyradiculoneuropathy
- PMID: 39223423
- DOI: 10.1007/s10072-024-07747-7
Charcot-Marie-Tooth type 2CC misdiagnosed as Chronic Inflammatory Demyelinating Polyradiculoneuropathy
Abstract
Background and aims: Charcot-Marie-Tooth (CMT) is a heterogeneous group of genetic neuropathies and is typically characterized by distal muscle weakness, sensory loss, pes cavus and areflexia. Herein we describe a case of CMT2CC presenting with proximal muscle weakness and equivocal electrophysiological features, that was misdiagnosed as chronic inflammatory demyelinating polyneuropathy (CIDP).
Case report: A 30-year-old woman complained of proximal muscle weakness with difficulty climbing stairs. Neurological examination showed weakness in lower limb (LL) muscles, that was marked proximally and mild distally, and absence of deep tendon reflexes in the ankles. Nerve conduction studies (NCS) showed sensory-motor neuropathy with non-uniform NC velocity and a partial conduction block (CBs) in peroneal nerve and tibial nerves. Thus, a diagnosis of CIDP was entertained and the patient underwent ineffective treatment with intravenous immunoglobulins. At electrophysiological revaluation CB in peroneal nerve was undetectable as also distal CMAP had decreased whereas the CBs persisted in tibial nerves. Hypothesizing a hereditary neuropathy, we examined the proband's son, who presented mild weakness of distal and proximal muscles at lower limbs. Neurophysiological investigation showed findings consistent with an intermediate-axonal electrophysiological pattern. A targeted-NGS including 136 CMT genes showed the heterozygous frameshift mutation (c.3057dupG; p.K1020fs*43) in the NEFH gene, coding for the neurofilament heavy chain and causing CMT2CC.
Interpretation: Diagnosis of a genetic neuropathy may be challenging when clinical features are atypical and/or electrophysiological features are misleading. The most common misdiagnosis is CIDP. Our report suggests that also CMT2CC patients with proximal muscle weakness and equivocal electrophysiological features might be misdiagnosed as CIDP.
Keywords: CIDP; CMT2CC; Charcot-Marie-tooth; Conduction block; NEFH.
© 2024. Fondazione Società Italiana di Neurologia.
Conflict of interest statement
References
-
- Pisciotta C, Shy ME (2023) Hereditary neuropathy. Handb Clin Neurol. ;195:609–617. https://doi.org/10.1016/B978-0-323-98818-6.00009-1 . PMID: 37562889
-
- Pipis M, Cortese A, Polke JM, Poh R, Vandrovcova J, Laura M, Skorupinska M, Jacquier A, Juntas-Morales R, Latour P, Petiot P, Sole G, Fromes Y, Shah S, Blake J, Choi BO, Chung KW, Stojkovic T, Rossor AM, Reilly MM (2022) Charcot-Marie-tooth disease type 2CC due to NEFH variants causes a progressive, non-length-dependent, motor-predominant phenotype. J Neurol Neurosurg Psychiatry 93(1):48–56. https://doi.org/10.1136/jnnp-2021-327186 Epub 2021 Sep 13. PMID: 34518334; PMCID: PMC8685631 - DOI - PubMed
-
- Aruta F, Severi D, Iovino A, Spina E, Barghigiani M, Ruggiero L, Iodice R, Santorelli FM, Manganelli F, Tozza S (2021) Proximal weakness involvement in the first Italian case of Charcot-Marie-tooth 2CC harboring a novel frameshift variant in NEFH. J Peripher Nerv Syst 26(2):231–234. https://doi.org/10.1111/jns.12454 Epub 2021 May 19. PMID: 33987933 - DOI - PubMed
-
- Al-Chalabi A, Andersen PM, Nilsson P, Chioza B, Andersson JL, Russ C, Shaw CE, Powell JF, Leigh PN (1999) Deletions of the heavy neurofilament subunit tail in amyotrophic lateral sclerosis. Hum Mol Genet. ;8(2):157 – 64. https://doi.org/10.1093/hmg/8.2.157 . PMID: 9931323
-
- Lee MK, Xu Z, Wong PC, Cleveland DW (1993) Neurofilaments are obligate heteropolymers in vivo. J Cell Biol 122(6):1337–1350. https://doi.org/10.1083/jcb.122.6.1337 PMID: 8376466; PMCID: PMC2119859 - DOI - PubMed
Publication types
MeSH terms
Supplementary concepts
LinkOut - more resources
Full Text Sources
Medical