themolecularbasisofmusculardystrophy(編輯修改稿)
2024-11-29 17:03 本頁(yè)面
【文章內(nèi)容簡(jiǎn)介】 truncated（刪節(jié)的） but mostly functional dystrophin is produced. In these BMD patients, the extent and progression of the muscle weakness is less severe. 如果基因的突變沒(méi)有完全打亂 “三子一窩”的基因閱讀框， 也就說(shuō)基因字母（核酣酸）缺 失或增加的數(shù)量能被 3整除， 沒(méi)有余數(shù)。這種情況下抗肌萎 縮蛋白被縮短或者拉長(zhǎng)，同時(shí) 基因的改變發(fā)生在非關(guān)鍵區(qū) 域，例如抗肌萎縮蛋白的中 段，使得抗肌萎縮蛋白仍然能 發(fā)揮部分的功能，這就形成了 良性的假肥大型進(jìn)行性肌營(yíng)養(yǎng) 不良。 BMD 假如抗肌萎縮蛋白的基因突變 完全打亂了基因閱讀框，也就 是缺失或增加的核酣酸數(shù)量不 能被 3整除，那么從基因突變的 位點(diǎn)直到抗肌萎縮蛋白的終 點(diǎn)，所有合成的氨基酸都是錯(cuò) 誤的，那么不完全的抗肌萎縮 蛋白無(wú)法發(fā)揮它的正常功能， 這樣就形成了杜氏進(jìn)行性肌營(yíng) 養(yǎng)不良。 inframe out of frame DMD The parison between Becker and Duchenne Normal dystrophin Staining around the rim of muscle fibers Absent dystrophin No staining around the rim of any muscle fibers Duchenne Muscular Dystrophy: Dystrophin staining（染色） Western blot of dystrophin Lane 1: Becker dystrophy。 Dystrophin has reduced abundance but normal size. Lane 2: Becker dystrophy。 Dystrophin has reduced size and abundance. Lane 3: Normal。 Dystrophin has normal size and amount. Lane 4: Duchenne dystrophy。 Almost no protein is present. Lane 5: Duchenne dystrophy。 Dystrophin has severely reduced abundance. Normal BMD DMD DMD amp。 BMD ? BMD is a less severe form ,in which the same protein dystrophin is present but is abnormal or greatly reduced in amount . ? An arbitary means of distinguishing the two disorders depends on whether the affected person can still walk at age 16 years. Duchenne muscular dystrophy is the most mon form of MD and primarily affects boys. Onset is between 3 and 5 years and the disorder progresses rapidly. Most boys are unable to walk by age 12. DMD occurs in about 1 in 3,500 male births, and affects approximately 8,000 boys and young men in the United States. Symptoms癥狀 WHAT HAPPENS TO THE VOLUNTARY MUSCLES OF SOMEONE WITH DMD ? Difficulty walking, such as being late in learning how to walk (more than 18 months old), having a waddling gait or walking on toes or balls of the feet. ? Difficulty running or jumping caus
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