Qu Y, Carpenter N J, Whetsell L, Smith S P, Say B
Chapman Institute of Medical Genetics, Tulsa, OK 74135, USA.
J Okla State Med Assoc. 1996 Nov;89(11):395-9.
Charcot-Marie-Tooth (CMT) disease (also called Hereditary Motor and Sensory Neuropathy) is an inherited peripheral neuropathy with a prevalence rate of 1 in 2,500. Charcot-Marie-Tooth disease type 1A (CMT1A), the most common autosomal dominant form of the disease, is associated with a duplication of a segment of chromosome 17 (17p11.2). In this report we present a three-generation family with CMT1A where simple sequence repeats (di- or tri-nucleotide repeats, also called microsatellites) were used in conjunction with polymerase chain reaction (PCR) to identify the duplication. The presence of three alleles or the presence of two alleles with a dosage ratio of 1:2 for the markers D17S839 and D17S921 indicates the presence of the duplicated segment in affected family members, whereas two alleles with a ratio of 1:1 indicate absence of the duplication. Several markers outside the duplication region which have two alleles with a dosage ratio of 1:1 were used as controls. Seven CMT1A patients in this family carry the CMT1A duplication. One 12-year-old boy who has not exhibited any clinical symptoms does not have the CMT1A duplication. We believe that this is a simple, rapid, and effective method to identify the CMT1A duplication in most patients suspected of having CMT1A.
夏科-马里-图斯（CMT）病（也称为遗传性运动和感觉神经病）是一种遗传性周围神经病，患病率为1/2500。1A型夏科-马里-图斯病（CMT1A）是该病最常见的常染色体显性形式，与17号染色体（17p11.2）的一段重复有关。在本报告中，我们展示了一个患有CMT1A的三代家庭，其中使用简单序列重复（二核苷酸或三核苷酸重复，也称为微卫星）结合聚合酶链反应（PCR）来识别这种重复。对于标记D17S839和D17S921，三个等位基因的存在或两个等位基因以1:2的剂量比存在表明受影响家庭成员中存在重复片段，而两个等位基因以1:1的比例存在则表明不存在重复。在重复区域之外的几个具有两个以1:1剂量比的等位基因的标记被用作对照。这个家庭中的7名CMT1A患者携带CMT1A重复。一名12岁未表现出任何临床症状的男孩没有CMT1A重复。我们认为这是一种在大多数疑似患有CMT1A的患者中识别CMT1A重复的简单、快速且有效的方法。
