Kress W, Mueller-Myhsok B, Ricker K, Schneider C, Koch M C, Toyka K V, Mueller C R, Grimm T
Division of Medical Genetics, University of Würzburg, Würzburg, Germany.
Neuromuscul Disord. 2000 Oct;10(7):478-80. doi: 10.1016/s0960-8966(00)00129-2.
Recently, myotonic dystrophy type 2 has been described as a separate disease entity that is distinctive from classical Steinert's disease since it lacks a CTG repeat expansion on chromosome 19q. A gene locus for myotonic dystrophy type 2 has been mapped to chromosome 3q. Independently, proximal myotonic myopathy has been recognized as yet another form of a multisystem myotonic disorder. Its relationship to myotonic dystrophy type 2 remains to be clarified. In our linkage study of 17 German proximal myotonic myopathy families nine of them mapped to the myotonic dystrophy type 2 locus (LOD score 18.9). However, two families with a typical proximal myotonic myopathy phenotype were excluded from this locus (LOD score -7.4). These results confirm genetic heterogeneity in the proximal myotonic myopathy syndrome. Furthermore, in the majority of the proximal myotonic myopathy families the disease phenotype may be caused by allelic mutations in the putative myotonic dystrophy type 2 gene.
最近，2型强直性肌营养不良被描述为一种独立的疾病实体，与经典的斯坦纳特病不同，因为它在19号染色体上缺乏CTG重复序列扩增。2型强直性肌营养不良的基因座已被定位到3号染色体上。另外，近端强直性肌病已被确认为多系统强直性疾病的另一种形式。它与2型强直性肌营养不良的关系仍有待阐明。在我们对17个德国近端强直性肌病家族的连锁研究中，其中9个家族定位于2型强直性肌营养不良基因座（对数优势计分18.9）。然而，两个具有典型近端强直性肌病表型的家族被排除在该基因座之外（对数优势计分-7.4）。这些结果证实了近端强直性肌病综合征中的遗传异质性。此外，在大多数近端强直性肌病家族中，疾病表型可能由假定的2型强直性肌营养不良基因中的等位基因突变引起。
