Comparison of two PCR-based molecular methods in the diagnosis of CMT 1A and HNPP diseases in Chinese

Objectives Current molecular diagnostic methods in detecting Charcot-Marie-Tooth type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsy (HNPP) diseases are either not sensitive or time-consuming and costing. The aims of this study are improving the accuracy and speeding up the diagnosis. Patients and methods We developed real-time quantitative PCR (QPCR) and three polymorphic short tandem repeats (STRs) methods to test 53 unrelated CMT1A patients, 12 unrelated HNPP patients and 100 normal control subjects. Results QPCR in detection of pmp22 gene duplication (CMT1A) and deletion (HNPP) showed a sensitivity of 100.00% (53/53) and 100.00% (12/12), respectively. And this method also showed a specificity of 100% (100/100) in CMT1A and 100% (100/100) in HNPP, respectively. In contrast, using three polymorphic STRs method showed a sensitivity of 50/53 (94%) in CMT1A and 12/12 (100.00%) of HNPP patients, respectively. And this method showed a specificity of 97% (100/103) in CMT1A and 100% (100/100) in HNPP, respectively. Conclusion QPCR and three STRs methods both demonstrate a rapid and robust diagnosis with almost complete informativeness. The high sensitivity and heterozygosity of these three polymorphic markers in detecting CMT1A/HNPP subjects of Caucasian and Chinese showed the potential to become pan-ethnic screening markers in the future.