Peking University Center of Medical Genetics, Peking University, Beijing, China.
Behav Brain Funct. 2008 Apr 29;4:20. doi: 10.1186/1744-9081-4-20.
DNA deletion and duplication were determined as the major mutation underlying Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD).
Applying multiplex ligation-dependent probe amplification (MLPA), we have analyzed 179 unrelated DMD/BMD subjects from northern China.
Seventy-three percent of the subjects were found having a deletion (66.25%) or duplication (6.25%). Exons 51-52 were detected as the most common fragment deleted in single-exon deletion, and the region of exons 45-50 was the most common exons deleted in multi-exon deletions. About 90% of DMD/BMD cases carry a small size deletion that involves 10 exons or less, 26.67% of which carry a single-exon deletion. Most of the smaller deletions resulted in an out-of-frame mutation. The most common exons deleted were determined to be between exon 48 and exon 52, with exon 50 was the model allele. Verifying single-exon deletion, one sample with a deletion of exon 53 that was initially observed from MLPA showed that there was a single base deletion that abolished the ligation site in MLPA. Confirmation of single-exon deletion is recommended to exclude single base deletion or mutation at the MLPA ligation site.
The frequency of deletion and duplication in northern China is similar to global ethnic populations.
DNA 缺失和重复被确定为导致杜氏肌营养不良症（DMD）和贝克肌营养不良症（BMD）的主要突变。
应用多重连接依赖性探针扩增（MLPA），我们分析了来自中国北方的 179 名无关的 DMD/BMD 患者。
73%的患者存在缺失（66.25%）或重复（6.25%）。在单外显子缺失中，检测到 51-52 号外显子最常见的缺失片段，在多外显子缺失中，最常见的缺失外显子区域为 45-50 号外显子。大约 90%的 DMD/BMD 病例携带 10 个外显子或更少的小尺寸缺失，其中 26.67%携带单外显子缺失。大多数较小的缺失导致移码突变。最常见的缺失外显子被确定在 48 号和 52 号外显子之间，50 号外显子是模型等位基因。验证单外显子缺失时，从 MLPA 最初观察到的缺失 53 号外显子的一个样本显示，存在一个单碱基缺失，使 MLPA 的连接点失效。建议确认单外显子缺失，以排除 MLPA 连接点的单碱基缺失或突变。
中国北方缺失和重复的频率与全球种族人群相似。
