HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Correspondence: Submit a response Alert me when this article is cited Alert me when Correspondence are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ptácek, L. J. Articles by Leppert, M. F. Search for Related Content PubMed PubMed Citation Articles by Ptácek, L. J. Articles by Leppert, M. F.

Sodium channel mutations in acetazolamide-responsive myotonia congenita, paramyotonia congenita, and hyperkalemic periodic paralysis

L. J. Ptáek, MD, R. Tawil, MD, R. C. Griggs, MD, G. Meola, MD, P. McManis, MD, R. J. Barohn, MD, J. R. Mendell, MD, C. Harris, MD, R. Spitzer, MD, F. Santiago, MD and M. F. Leppert, PhD

Departments of Neurology (Drs. Ptáek and Santiago), Human Genetics (Drs. Ptáek and Leppert), and Pathology (Dr. Harris), and the Howard Hughes Medical Institute (Dr. Leppert), University of Utah Health Sciences Center, Salt Lake City, UT; the Department of Neurology (Drs. Tawil and Griggs), University of Rochester School of Medicine, Rochester, NY; the Department of Neurology (Dr. Meola), Università Degli Studi Di Mi-lano, Milan, Italy; the Department of Neurology (Dr. McManis), Mayo Clinic, Rochester, MN; the Department of Medicine (Dr. Barohn), Division of Neurology, University of Texas Health Sciences Center, San Antonio, TX; the Department of Neurology (Dr. Mendell), Ohio State University, Columbus, OH; and Huntington Memorial Hospital (Dr. Spitzer), Pasadena, CA.

Hyperkalemic periodic paralysis (hyperKPP) and paramyotonia congenita (PC) are genetic muscle disorders sharing the common features of myotonia and episodic weakness. In hyperKPP, patient symptoms and signs are worsened by elevated serum potassium, whereas in PC, muscle cooling exacerbates the condition. There are patients in whom features of both hyperKPP and PC are present. These diseases result from molecular alterations in the adult skeletal muscle sodium channel. This report summarizes our sodium channel mutation analysis in 25 families with hyperKPP and PC. We also report the putative disease-causing mutation in acetazolamide-responsive myotonia congenita, a related disease in which myotonia is worsened by potassium but in which episodic weakness does not occur. This missense mutation (I1160V) occurs at a very highly conserved position in the sodium channel, cosegregates with the disease, and was not present in any of a large panel of normal DNAs. Electrophysiologic characterization of specific mutations will lead to better understanding of the biophysics of this voltage-gated ion channel.

Address correspondence and reprint requests to Dr. L.J. Ptáek, Department of Neurology, University of Utah Health Sciences Center, 50 North Medical Drive, Salt Lake City, UT 84132.

Supported by NIH grant no. 1 K11 HD00940 (to L.J.P.), by an MDA fellowship to R.T., by Public Health Service research grant no. M01-RR00064 from the National Center for Research Resources, by the Howard Hughes Medical Institute, and by the Utah Technology Access Center (NIH grant no. 8 R01 HG00367 from the Center for Human Genome Research).

Received September 15, 1993. Accepted in final form February 8, 1994.