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. ? 2008 Elsevier B.V. All rights reserved.