A case report of type 1 diabetes mellitus coexistent with Charcot–Marie–Tooth type 1A and a literature review

Introduction

Charcot–Marie–Tooth disease (CMTD) is a common group of single-gene hereditary neuropathy characterized by chronic progressive exacerbation of distal limb weakness, sensory abnormalities, and nerve conduction dysfunction. It can be grouped into various subtypes based on the median nerve motor conduction velocity (MNCV) and gene mapping. CMTD1A is the most common subtype, accounting for > 50% of all subtypes, caused by the duplication of the peripheral myelin protein 22 (PMP22) gene on chromosome 17. Diabetes mellitus is a common metabolic disorder that frequently causes predominant sensory neuropathy. Diabetes with CMTD is not commonly reported. Especially diabetes type 1 (T1D) with CMTD1A has not been reported so far. This study reports a case of T1D with CMTD1A diagnosed by a gene test.

Results

Upon the clinical manifestations, physical examination, EMG and genetic testing results, we diagnosed the patient as T1D with CMTD1A, and the related literatures were reviewed.

Conclusion

It is not yet clear whether there is a genetic association between the CMTD and diabetes, the genes causing CMTD are perhaps related to T1D and T2D genes. When CMTD and diabetes coexist, the resulting neuropathy is more severe than that observed with either condition alone. We recommend that such patients should strictly control their blood-glucose level to slow down the progression of the disease.