BACKGROUND: Over the past 3 years, the genetics of the myotonic diseases have been substantially elaborated. Three genetically different groups of myotonic disease can be discerned: (1) the chloride channel myotonias, (2) the adynamia-paramyotonia complex, and (3) myotonic dystrophy. METHODS AND RESULTS: Electrophysiology has suggested and molecular biology has proven that the diseases belonging to the adynamia-paramyotonia complex, ie, paramyotonia congenita, hyperkalemic and normokalemic periodic paralysis, and some rare forms of myotonic disease, are caused by point mutations in the gene encoding the alpha subunit of the sodium channel in adult human skeletal muscle, located on chromosome 17q23. Thirteen different mutations have been described by various groups in the United States and Germany. The various mutations causing a particular form of the complex are not located in the gene in a predictable or easily understandable regular manner. CONCLUSIONS: Further study of the genotype-phenotype correlations should not only increase our understanding of the variability of signs in this group of diseases, it could also provide us with a deeper insight in the function of the various regions of the sodium channel protein.
BACKGROUND: Over the past 3 years, the genetics of the myotonic diseases have been substantially elaborated. Three genetically different groups of myotonic disease can be discerned: (1) the chloride channel myotonias, (2) the adynamia-paramyotonia complex, and (3) myotonic dystrophy. METHODS AND RESULTS: Electrophysiology has suggested and molecular biology has proven that the diseases belonging to the adynamia-paramyotonia complex, ie, paramyotonia congenita, hyperkalemic and normokalemic periodic paralysis, and some rare forms of myotonic disease, are caused by point mutations in the gene encoding the alpha subunit of the sodium channel in adult human skeletal muscle, located on chromosome 17q23. Thirteen different mutations have been described by various groups in the United States and Germany. The various mutations causing a particular form of the complex are not located in the gene in a predictable or easily understandable regular manner. CONCLUSIONS: Further study of the genotype-phenotype correlations should not only increase our understanding of the variability of signs in this group of diseases, it could also provide us with a deeper insight in the function of the various regions of the sodium channel protein.
Authors: Ivy E Dick; Worawan B Limpitikul; Jacqueline Niu; Rahul Banerjee; John B Issa; Manu Ben-Johny; Paul J Adams; Po Wei Kang; Shin Rong Lee; Lingjie Sang; Wanjun Yang; Jennifer Babich; Manning Zhang; Hojjat Bazazzi; Nancy C Yue; Gordon F Tomaselli Journal: Channels (Austin) Date: 2015-07-15 Impact factor: 2.581
Authors: Bas C Stunnenberg; Samantha LoRusso; W David Arnold; Richard J Barohn; Stephen C Cannon; Bertrand Fontaine; Robert C Griggs; Michael G Hanna; Emma Matthews; Giovanni Meola; Valeria A Sansone; Jaya R Trivedi; Baziel G M van Engelen; Savine Vicart; Jeffrey M Statland Journal: Muscle Nerve Date: 2020-05-27 Impact factor: 3.217
Authors: G F Tomaselli; N Chiamvimonvat; H B Nuss; J R Balser; M T Pérez-García; R H Xu; D W Orias; P H Backx; E Marban Journal: Biophys J Date: 1995-05 Impact factor: 4.033
Authors: N Mitrović; A L George; R Heine; S Wagner; U Pika; U Hartlaub; M Zhou; H Lerche; C Fahlke; F Lehmann-Horn Journal: J Physiol Date: 1994-08-01 Impact factor: 5.182