Background: Hereditary neuropathy with liability to pressure palsy (HNPP), mainly associated with the peripheral myelin protein 22 (PMP22) gene, is generally an autosomal-dominant inherited peripheral neuropathy. The present large family including four generations provides an exciting opportunity to gain important insights into HNPP in China. Patients and Methods: A large 43-member family with ten members suspected to be affected by HNPP was studied. Neurologic examinations, electrophysiological and neuropathological studies and molecular genetic testing were used for these kindred. Results: Clinically, the proband had limb hyposthenia and atrophy, and his mother showed declined tendon reflexes in the right lower limb. Electrophysiologically, sensory and motor nerve conduction velocities were generalized reduced. Sural nerve biopsy for the proband showed focal thickesning of the myelin sheaths. Furthermore, real-time quantitative PCR demonstrated that the PMP22 gene has a higher Ct value than reference gene in all suspected patients. Conclusions: These results indicated that the family is indeed a rare and large pedigree of HNPP caused by the deletion of PMP22 gene. Given that the suspected patient in the fourth generation is absent, this family is still worthy of further follow-up study.

1.
Stogbauer F, Young P, Kuhlenbaumer G, De Jonghe P, Timmerman V: Hereditary recurrent focal neuropathies: clinical and molecular features. Neurology 2000;54:546–551.
2.
Chance PF: Inherited focal, episodic neuropathies: hereditary neuropathy with liability to pressure palsies and hereditary neuralgic amyotrophy. Neuromolec Med 2006;8:159–174.
3.
Vital A, Vital C, Latour P, Ferrer X, Rouanet-Larivière M, Brechenmacher C, Lagueny A: Peripheral nerve biopsy study in 19 cases with 17p11.2 deletion. J Neuropathol Exp Neurol 2004;63:1167–1172.
4.
Luigetti M, Conte A, Madia F, Mereu ML, Zollino M, Marangi G, Pomponi MG, Liberatore G, Tonali PA, Sabatelli M: A new single-nucleotide deletion of PMP22 in an HNPP family without recurrent palsies. Muscle Nerve 2008;38:1060–1064.
5.
Mouton P, Tardieu S, Gouider R, Birouk N, Maisonobe T, Dubourg O, Brice A, LeGuern E, Bouche P: Spectrum of clinical and electrophysiologic features in hnpp patients with the 17p11.2 deletion. Neurology 1999;52:1440–1446.
6.
Kabzinska D, Pierscinska J, Kochanski A: Screening of the 17p11.2–p12 region in a large cohort of patients with Charcot-Marie-Tooth (CMT) disease or hereditary neuropathy with liability to pressure palsies (HNPP). J Appl Genet 2009;50:283–288.
7.
Sanahuja J, Franco E, Rojas-Garcia R, Gallardo E, Combarros O, Begue R, Granes P, Illa I: Central nervous system involvement in hereditary neuropathy with liability to pressure palsies: description of a large family with this association. Arch Neurol 2005;62:1911–1914.
8.
Kimura J: Principles and variations of nerve conduction studies; in Kimura J (ed): Electrodiagnosis in Disease of Nerve and Muscle: Principles and Practice, ed 3. New York, Oxford University Press, 2001, pp 91–129.
9.
Dyck PJ, Dyck PJB, Engelstad J: Pathological alterations of nerves; in Dyck PJ, Thomas PK (eds): Peripheral Neuropathy. Philadelphia, Elsevier Saunders, 2005, pp 733–829.
10.
Yoshikawa H, Dyck PJ: Uncompacted inner myelin lamellae in inherited tendency to pressure palsy. J Neuropathol Exp Neurol 1991;50:649–657.
11.
Thiel CT, Kraus C, Rauch A, Ekici AB, Rautenstrauss B, Reis A: A new quantitative PCR multiplex assay for rapid analysis of chromosome 17p11.2–12 duplications and deletions leading to HMSN/HNPP. Eur J Hum Genet 2003;11:170–178.
12.
Kim SW, Lee KS, Jin HS, Lee TM, Koo SK, Lee YJ, Jung SC: Rapid detection of duplication/deletion of the PMP22 gene in patients with Charcot-Marie-Tooth disease type 1A and hereditary neuropathy with liability to pressure palsy by real-time quantitative PCR using SYBR Green I dye. J Korean Med Sci 2003;18:727–732.
13.
Andersson PB, Yuen E, Parko K, So YT: Electrodiagnostic features of hereditary neuropathy with liability to pressure palsies. Neurology 2000;54:40–44
14.
Madrid R, Bradley WG: The pathology of neuropathies with focal thickening of the myelin sheath (tomaculous neuropathy): studies on the formation of the abnormal myelin sheath. J Neurol Sci 1975;25:415–488.
15.
De Jong JGY: Over families met hereditaire dispositie ot het optreden van neuritiden gecorreleered met migraine. Psychiatr Neurol B 1947:50.
16.
Dubourga O: Guidelines for diagnosis of hereditary neuropathy with liability to pressure palsies. Neuromuscul Disord 2000;10:206–208.
17.
Pareyson D, Scaioli V, Taroni F, Botti S, Lorenzetti D, Solari A, Ciano C, Sghirlanzoni A: Phenotypic heterogeneity in hereditary neuropathy with liability to pressure palsies associated with chromosome 17p11.2–12 deletion. Neurology 1996;46:1133–1137.
18.
Behse F, Buchthal F, Carlsen F, Knappeis GG: Hereditary neuropathy with liability to pressure palsies. Electrophysiological and histopathological aspects. Brain 1972;95:777–794.
19.
Bai Y, Zhang X, Katona I, Saporta MA, Shy ME, O’Malley HA, Isom LL, Suter U, Li J: Conduction block in PMP22 deficiency. J Neurosci 2010;30:600–608.
20.
Korn-Lubetzki I, Argov Z, Raas-Rothschild A, Wirguin I, Steiner I: Family with inflammatory demyelinating polyneuropathy and the hnpp 17p12 deletion. Am J Med Genet 2002;113:275–278.
21.
Inoue K, Dewar K, Katsanis N, Reiter LT, Lander ES, Devon KL, Wyman DW, Lupski JR, Birren B: The 1.4-Mb CMT1A duplication/HNPP deletion genomic region reveals unique genome architectural features and provides insights into the recent evolution of new genes. Genome Res 2001;11:1018–1033.
22.
Infante J, Garcia A, Combarros O, Mateo JI, Berciano J, Sedano MJ, Gutierrez-Rivas EJ, Palau F: Diagnostic strategy for familial and sporadic cases of neuropathy associated with 17p11.2 deletion. Muscle Nerve 2001;24:1149–1155.
23.
Muglia M, Patitucci A, Rizzi R, Ungaro C, Conforti FL, Gabriele AL, Magariello A, Mazzei R, Motti L, Sabadini R, Sprovieri T, Marcello N, Quattrone A: A novel point mutation in PMP22 gene in an Italian family with hereditary neuropathy with liability to pressure palsies. J Neurol Sci 2007;263:194–197.
24.
Zhang FF, Tang BS, Shen Y, Zhao GH, Xia K, Zhao YQ, Chen B, Zhang C, Pan Q, Cai F, Liu XM, Luo W, Zhang RX, Guo P: Detection of duplications or deletions of the PMP22 gene using real-time quantitative PCR. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 2005;22:537–540.
25.
Cui F, Hung XS, Chen ZH: Clinical, electrophysiological, pathological and genomic study of hereditary liability to pressure palsies. J HMC 2010;16:407–410.
26.
Chen SR, Lin KP, Kuo HC, Chen CM, Hsieh ST, Lee MJ, Yang CC, Liu CS, Huang CC, Lyu RK, Ro LS: Comparison of two PCR-based molecular methods in the diagnosis of CMT1A and HNPP diseases in Chinese. Clin Neurol Neurosurg 2008;110:466–471.
27.
Kim SM, Chung KW, Choi BO, Yoon ES, Choi JY, Park KD, Sunwoo IN: Hereditary neuropathy with liability to pressure palsies (HNPP) patients of Korean ancestry with chromosome 17p11.2-p12 deletion. Exp Mol Med 2004;36:28–35.
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