Background: Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are common X-linked recessive neuromuscular disorders caused by mutations in dystrophin gene. Multiplex polymerase chain reaction (multiplex PCR) and multiplex ligation-dependent probe amplification (MLPA) are the most common methods for detecting dystrophin gene mutations. This study aimed to contrast the two methods and discern the genetic characterization of patients with DMD/BMD in Eastern China.
Methods: We collected 121 probands, 64 mothers of probands, and 15 fetuses in our study. The dystrophin gene was detected by multiplex PCR primarily in 28 probands, and MLPA was used in multiplex PCR-negative cases subsequently. The dystrophin gene of the remaining 93 probands and 62 female potential carriers was tested by MLPA directly. In fetuses, multiplex PCR and MLPA were performed on 4 fetuses and 10 fetuses, respectively. In addition, sequencing was also performed in 4 probands with negative MLPA.
Results: We found that 61.98% of the subjects had genetic mutations including deletions (50.41%) and duplications (11.57%). There were 43.75% of mothers as carriers of the mutation. In 15 fetuses, 2 out of 7 male fetuses were found to be unhealthy and 2 out of 8 female fetuses were found to be carriers. Exons 3-26 and 45-52 have the maximum frequency in mutation regions. In the frequency of exons individually, exon 47 and exon 50 were the most common in deleted regions and exons 5, 6, and 7 were found most frequently in duplicated regions.
Conclusions: MLPA has better productivity and sensitivity than multiplex PCR. Prenatal diagnosis should be applied in DMD high-risk fetuses to reduce the disease incidence. Furthermore, it is the responsibility of physicians to inform female carriers the importance of prenatal diagnosis.
基于分子诊断技术的中国东部地区杜氏肌营养不良/贝氏肌营养不良患者基因突变分析摘要背景：杜氏肌营养不良症（DMD）和贝氏肌营养不良症（BMD）是抗肌萎缩蛋白基因突变导致的常见神经肌肉疾病，为X连锁隐性遗传。多重聚合酶链式反应技术（mPCR）和多重连接探针扩增技术(MLPA)是检测抗肌萎缩蛋白基因突变的常用方法。本研究旨在比较这两种方法以及总结中国东部地区DMD/BMD患者的基因突变特征。 方法：本研究中，我们收集了先证者121例，先证者母亲64例以及胎儿15例。28例先证者抗肌萎缩蛋白基因使用mPCR检测，MLPA用于检测mPCR阴性病例，其余93例先证者和62例女性潜在携带者直接进行MLPA检测。在胎儿中，分别对4例胎儿和10例胎儿进行mPCR技术和MLPA检测。此外，四例MLPA阴性先证者通过测序方法进行检测。 结果：我们发现61.98％的受试者有基因突变，包括缺失突变(50.41％)和重复突变(11.57％)。43.75％的母亲为携带者。在15例胎儿中，7例男性胎儿中有2例为患者，8例女性胎儿中有2例为携带者。外显子3-26和45-52在突变区域呈现出最高突变频率。在单个外显子突变频率统计中，在缺失突变中，外显子47和外显子50最为常见；而在重复突变中，外显子5,6,7最为常见。 结论：MLPA在检测率和灵敏度上优于mPCR。产前诊断应该用于患病高危胎儿以降低疾病发病率。此外，医生有责任让女性携带者了解产前诊断的重要性。.
Keywords: Becker Muscular Dystrophy; Duchenne Muscular Dystrophy; Dystrophin; Multiplex Ligation-dependent Probe Amplification; Multiplex Polymerase Chain Reaction; Prenatal Diagnosis.