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

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Clin Neurol Neurosurg. 2008 Mar 17

Comparison of two PCR-based molecular methods in the diagnosis of CMT

1A and HNPP diseases in Chinese.

Chen SR, Lin KP, Kuo HC, Chen CM, Hsieh ST, Lee MJ, Yang CC, Liu CS,

Huang CC, Lyu RK, Ro LS.

Section of Neuromuscular Disorders, Department of Neurology, Chang

Gung Memorial Hospital and University, 199 Tun Hwa North Road, Taipei

10591, Taiwan.

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.