Analysis On The Clinic, Pathology And PMP22Gene Of Charcot-Marie-Tooth Disease

ObjectiveTo observe the clinical manifestations, neuron-electrophysiology and nervepathology biopsy features of Charcot-Marie-Tooth disease. To detect thePMP22gene in the patients with CMT by using allele-specific PCR andmultiplex ligation-dependent probe amplification (MLPA). Investigate thecorrelation of the clinical, neuron-electrophysiology, nerve pathology andgenetic changes of CMT. Simply validate if the results of the two methods areconsistent. In order to guide to establish the screening program for clinical onPMP22gene duplication mutation.MethodsFourteen cases of patients with CMT collected in clinical underwent detailedclinical and neuron-electrophysiology examinations.5cases of them underwentthe nerve pathology biopsy. Extracted venous blood in all patients and extractedthe DNA in their blood. Respectively used allele-specific PCR and multiplexligation-dependent probe amplification (MLPA) to do the detection of PMP22gene duplication mutation for all cases of patients.ResultsThe age of onset in most CMT patients was in the first or second decade.The clinical features were slowly progressive weakness and atrophy of distalmuscle and sensory decrement of distal limbs and diminished or absent oftendon reflexes. There were foot deformities with9patients. The EMG showedhighly decreased of conduction velocities and slightly decreased of volatility.The nerve biopsy showed extensive demyelization with or without axonaldegeneration. Secondary axonal degeneration was more prominent in the peripheral nerve pathology among the patients with axonal dysfunction by thedetection of EMG.7patients were found to exist the PMP22gene duplicationmutation by the two genetic testing methods of allele-specific PCR and multiplexligation-dependent probe amplification (MLPA),but the other7patients were notdetected to exist the PMP22gene duplication mutation by this two methods.The results were consistent with two methods.ConclusionsThe disease of CMT usually begins in childhood or adolescence. Its clinicalfeatures include progressive weakness and atrophy of distal muscles. The EMGshowed highly decreased of conduction velocities and slightly decreased ofvolatility. The nerve biopsy showed extensive demyelization with or withoutaxonal degeneration. Secondary axonal degeneration were more prominent inthe peripheral nerve pathology among the patients with axonal dysfunction bythe detection of EMG. PMP22gene detected can help the diagnosis ofCMT1A.The allele-specific PCR is consistent with multiplex ligation-dependentprobe amplification type (MLPA) in detecting PMP22gene duplication mutationin CMT patients. Under the conditions of clinical patients screening and thelaboratory with simple equipments, we can first use the allele-specific PCR andthen choose the MLPA which with higher sensitivity and accuracy to detect thesuspicious-positive patients to definite the diagnosis.