The convergence of genetic neuropathies and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is widely acknowledged. Key considerations such as disease progression, familial medical history, and an inadequate response to Intravenous Immunoglobulin (IVIG) therapy should trigger suspicion of an inherited neuropathy, such as Charcot-Marie-Tooth (CMT), with PMP22 gene mutation being the most prevalent. Furthermore, individuals with an INF2 gene mutation may concurrently manifest CMT neuropathy along with renal disorders. INF2 promotes the synthesis of a formin protein involved in myelination and its maintenance, potentially contributing to the emergence of CMT.

 A 30-year-old woman initially presented since childhood with bilateral distal weakness in her feet and hands, along with numbness in both hands with slow progression for many years. She also presented a subacute onset of proximal weakness. Additionally, she had a nerve conduction study demonstrating conduction block and a cerebrospinal fluid analysis indicating albumino-cytological dissociation. These findings led to the diagnosis of CIDP She received (IVIG) treatment, resulting in partial symptom improvement. However, the weakness and numbness complaints persisted. Subsequent physical examinations revealed symmetrical distal hyporeflexia in both upper and lower limbs and distal atrophy. She continued to seek care at the neuromuscular diseases outpatient clinic due to neuropathic pain. Eighteen years later, she noticed foamy urine. Genetic testing for hereditary neuropathies showed a pathogenic variant in the PMP22 gene and a mutation in the INF2 gene. Notably, our patient presented with severe proteinuria, and is still under investigation in the nephrology service to confirm the diagnosis.

This represents a rare case of CMT co-occurring with CIDP in a patient harboring mutations in the PMP22 and INF2 genes, further complicated by the late onset of glomerulopathy. Mutations in INF2 have been linked to the intricate clinical manifestations of CMT and renal disease, although causality with CIDP cannot be conclusively inferred.