伪埃克松通过深层内基变体和表型变异激活在一个中国家族的dystrophinopathy
Xingyu Xia1,2,3, Kexin Jiao1,2,3, Chaoping Hu4
1Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
Journal of human genetics
|June 29, 2025
概括
双基因 (DMD) 中的一种深层内基变异通过激活mRNA中的伪子 (PE) 来引起杜氏肌肉发育不良 (DMD). 这种拼接缺陷导致几乎完全丧失了双蛋白.
科学领域:
- 遗传学 遗传学 是一个
- 分子生物学分子生物学
- 神经肌肉疾病 神经肌肉疾病
背景情况:
- 在mRNA中包含异常的伪exon (PE) 是一种罕见的拼接缺陷,涉及杜氏肌肉发育不良 (DMD).
- 在DMD中诊断导致拼接缺陷的内基变异可能具有挑战性.
研究的目的:
- 调查在两名患有杜氏肌肉发育不良症的中国男性中发现的DMD基因中一个深层内突变的分子机制.
- 确认已识别的变种的致病性及其在DMD病变发生中的作用.
主要方法:
- 全基因组测序和基于链接的过以识别遗传变异.
- 利用患者衍生的诱导性多能干细胞 (iPSCs),并将其分化为神经管用于功能研究.
- 定量PCR (qPCR) 用于评估异常的转录水平和西部抹杀 (暗示通过基蛋白表达) 以评估蛋白质水平.
主要成果:
- 在DMD基因的47号内突中发现了一个深层内突变 (c.6913-4037T>G).
- 这种变体激活了一个神秘的拼接部位,导致在DMD mRNA中的第47和第48个外显子之间包含72bp的伪外显子 (PE).
- 含有PE的异常转录是非常丰富的 (约89%在肌管中,约97%在肌肉中),导致几乎完全丧失了双氨酸表达.
- 来自患者的肌管表现出受损的融合和改变的信号传递.
结论:
- 深层内部变异c.6913-4037T>G是致病性,并通过伪埃克松的含入和随后的失去了dystrophin引起杜申肌肉发育不良.
- 这一发现突显了与内在DMD变体相关的诊断复杂性,并扩大了DMD的突变谱.
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