Kidd A, Turnpenny P, Kelly K, Clark C, Church W, Hutchinson C, Dean J C, Haites N E
Department of Medical Genetics, Aberdeen Royal Infirmary, Foresterhill, UK.
J Med Genet. 1995 Jul;32(7):519-23. doi: 10.1136/jmg.32.7.519.
Myotonic dystrophy (DM) almost always results from the expansion of an unstable (CTG)n repeat. The mutation can be detected directly. Affected patients with cataracts may have minimal additional signs of the disorder, but all are at risk of life threatening complications. We have studied the efficacy of detecting new families with myotonic dystrophy by selectively screening cataract patients. Selection criteria were: age under 60 with no obvious precipitating factor (except non-insulin dependent diabetes mellitus (NIDDM)); patients of any age with other signs suggestive of myotonic dystrophy detected by the ophthalmologist. Ninety-six patients were tested prospectively; 17 others under 55 were screened retrospectively. All patients were counselled by a clinical geneticist before testing. The patients' DNA was analysed using the DNA probe/restriction enzyme combinations GB2.6/EcoRI, KB1.4/BglI and polymerase chain reaction (PCR). Six patients have been found to have a mutation, three (3.1%) in the prospective group and three (17.6%) in the retrospective group. Three of these patients had minimal myotonic dystrophy and three had classical DM.
强直性肌营养不良（DM）几乎总是由不稳定的（CTG）n重复序列扩增所致。该突变可直接检测到。患有白内障的受影响患者可能仅有该疾病的极少其他体征，但所有人都有发生危及生命并发症的风险。我们研究了通过选择性筛查白内障患者来检测强直性肌营养不良新家族的有效性。选择标准为：年龄在60岁以下且无明显诱发因素（非胰岛素依赖型糖尿病（NIDDM）除外）；任何年龄的患者，眼科医生检测到有其他提示强直性肌营养不良的体征。对96例患者进行了前瞻性检测；对另外17例55岁以下的患者进行了回顾性筛查。所有患者在检测前均由临床遗传学家提供咨询。使用DNA探针/限制性内切酶组合GB2.6/EcoRI、KB1.4/BglI和聚合酶链反应（PCR）对患者的DNA进行分析。已发现6例患者存在突变，前瞻性组3例（3.1%），回顾性组3例（17.6%）。这些患者中有3例患有轻度强直性肌营养不良，3例患有典型的DM。
