The fragile X syndrome: no evidence for any recent mutations.
The fragile X syndrome: no evidence for any recent mutations.
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脆性 X 综合征：没有任何近期突变的证据。
DOI：
10.1136/jmg.30.2.94
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发表时间：
1993
影响因子：
4
通讯作者：
F. M. Dreesen
中科院分区：
文献类型：
--
作者：
A. Smits;J. Dreesen;J. Post;D. F. C. M. Smeets;C. D. Die;Spaans;L. Govaerts;S. Warren;B. Oostra;B. A. V. Oost;F. M. Dreesen
脆性X染色体（fra(X)）综合征是家族性智力低下的最常见形式，是由由CGG重复序列组成的遗传性不稳定DNA引起的。由于fra(X)患者的生殖健康严重受损，高突变率被认为可以解释其高患病率。然而，到目前为止，我们还没有发现84个先证者有任何新的突变。我们在这里展示了相同的fra(X)基因在五个fra(X)先证者，他们的共同祖先在1747年结婚。缺乏新的fra(X)突变意味着人群中的fra(X)基因携带者一定比以前认识到的要多得多。由于现在可以通过DNA分析检测无症状的fra(X)基因携带者，因此建议对任何新的先证者进行扩展家族研究。一个家庭说明了fra(X)载流子测定的重要性。
Fragile X (fra(X)) syndrome, the most common form of familial mental retardation, is caused by heritable unstable DNA composed of CGG repeats. As reproductive fitness of fra(X) patients is severely compromised, a high mutation rate has been proposed to explain the high prevalence. However, we have been unable to show any new mutation for 84 probands referred to us to date. We show here the same fra(X) gene in five fra(X) probands with common ancestors married in 1747. The lack of new fra(X) mutations implies that there must be many more fra(X) gene carriers in the population than previously realised. As it is now possible to detect asymptomatic fra(X) gene carriers by DNA analysis, extended family studies for any new proband are recommended. A family illustrating the importance of fra(X) carriership determination is reported.