O'Hoy K L, Tsilfidis C, Mahadevan M S, Neville C E, Barceló J, Hunter A G, Korneluk R G
Department of Microbiology and Immunology, University of Ottawa, Canada.
Science. 1993 Feb 5;259(5096):809-12. doi: 10.1126/science.8094260.
Myotonic dystrophy (DM) is an autosomal-dominant disorder that affects 1 in 8000 individuals. Amplification of an unstable trinucleotide CTG repeat, located within the 3' untranslated region of a gene, correlates with a more severe DM phenotype. In three cases, the number of CTG repeats was reduced during the transmission of the DM allele; in one of these cases, the number was reduced to within the normal range and correlated at least with a delay in the onset of clinical signs of DM. Haplotype data of six polymorphic markers in the DM gene region indicate that, in this latter case, two stretches of the affected chromosome had been exchanged with that region of the wild-type chromosome.
强直性肌营养不良（DM）是一种常染色体显性疾病，发病率为八千分之一。位于某基因3'非翻译区的不稳定三核苷酸CTG重复序列的扩增与更严重的DM表型相关。在三个病例中，DM等位基因在传递过程中CTG重复序列的数量减少；在其中一个病例中，该数量减少至正常范围内，且至少与DM临床症状出现的延迟相关。DM基因区域六个多态性标记的单倍型数据表明，在后一种情况下，受影响染色体的两段与野生型染色体的该区域发生了交换。
