Charcot Marie Tooth disease type 4C with overlap of chronic infammatory demyelinating polyneuropathy: a case report

Case presentation: Patient female, born of a cousin marriage with history of respiratory distress at birth requiring orotracheal intubation and was diagnosed with dysphagia requiring gastrostomy for 1 year. Presented neuropsychomotor developmental delay and at the age of 6 started with symptoms of paraesthesias and lower limbs cramps. At the age of 12, the patient presented muscle weakness and pain in the lower limbs with progressive worsening associated with frequent falls. The patient was referred to our service at the age of 13 years old. At clinical evaluation, the patient could easily stand up, initiate independent gait, with a wide-based gait and tendency to fall. She could stand without support for a short period of time. Presented Grade III muscle strength in lower limbs and grade IV in the upper limbs associated with hypotrophy in lower limbs and at reflex and sensitivity examinations presented hypoactive osteotendinous reflexes in upper limbs and absent in lower limbs with distally reduced sensitivity in the lower limbs. Electroneuromyography demonstrated severe peripheral sensorimotor demyelinating polyneuropathy and cerebrospinal fluid shown hiperproteynorraquia. During follow-up, the patient presented an unstable course of symptoms, with worsen of weakness especially in association with an infectious condition. Therefore, pulse therapy with steroids was chosen as a treatment, with expressive improvement of the clinical symptoms. PMP22 genetic test was performed, which ruled out Charcot Marie Tooth type 1A. An expansion of the genetic test was performed, which revealed CMT4C alteration with mutation in the SH3TC2 gene.

Discussion: Charcot Marie Tooth 4C disease is a chronic sensorimotor demyelinating polyneuropathy. It's the most frequent mutation among the recessive subtype but is considered a very rare form. In general, the mutation in the SH3TC2 gene characterizes a late-onset condition. In the case reported, we considered the coexistence between Charcot Marie Tooth disease type 4C and chronic demyelinating inflammatory polyneuropathy (CIDP). The findings that favor the diagnosis of overlap are the unstable course of symptoms, sensory symptoms, hyperproteinorraquia and clinical improvement after pulse therapy.

Final comments: The diagnosis of inflammatory polyneuropathy overlap in patients with Charcot Marie Tooth with unstable clinical course is important, due to the possibility of the clinical improvement when immunomodulatory and/or immunosuppressive therapy is indicated.

 

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
18 September 2023