PLOS GENETICS：研究发现与肌营养不良症有关联基因

法国研究人员最新发现一个与面肩肱型肌营养不良症有关联的重要基因，这将有助于研发治疗这种疾病的新疗法。

法国某研究小组日前通过小鼠实验发现，如果切除一个名为FAT1的基因，小鼠面部肌肉和局部肩部肌肉就会发育不正常，成年后肌肉也会过早萎缩。此外，该基因被切除的小鼠还会表现出视网膜血管异常和内耳畸形。这些症状与人类患面肩肱型肌营养不良症的症状极为相似。

研究人员深入研究后发现，面肩胛肱型肌营养不良症患者在胎儿阶段FAT1基因的表达程度就显着低于正常人，出生后这种基因发生变异的几率也较正常人高。

研究人员指出，FAT1基因在导致面肩肱型肌营养不良症的多种基因机制中均扮演重要角色，可以针对这个基因研发治疗这种疾病的新方法。

面肩肱型肌营养不良症是由4号染色体异常导致的一种肌营养不良症，症状主要表现为脸、肩和上臂肌力减退以及肌肉萎缩。

相关论文已经发表在新一期美国《科学公共图书馆—遗传卷》月刊上。

Deregulation of the Protocadherin Gene FAT1 Alters Muscle Shapes: Implications for the Pathogenesis of Facioscapulohumeral Dystrophy
Abstract
Generation of skeletal muscles with forms adapted to their function is essential for normal movement. Muscle shape is patterned by the coordinated polarity of collectively migrating myoblasts. Constitutive inactivation of the protocadherin gene Fat1 uncoupled individual myoblast polarity within chains, altering the shape of selective groups of muscles in the shoulder and face. These shape abnormalities were followed by early onset regionalised muscle defects in adult Fat1-deficient mice. Tissue-specific ablation of Fat1 driven by Pax3-cre reproduced muscle shape defects in limb but not face muscles, indicating a cell-autonomous contribution of Fat1 in migrating muscle precursors. Strikingly, the topography of muscle abnormalities caused by Fat1 loss-of-function resembles that of human patients with facioscapulohumeral dystrophy (FSHD). FAT1 lies near the critical locus involved in causing FSHD, and Fat1 mutant mice also show retinal vasculopathy, mimicking another symptom of FSHD, and showed abnormal inner ear patterning, predictive of deafness, reminiscent of another burden of FSHD. Muscle-specific reduction of FAT1 expression and promoter silencing was observed in foetal FSHD1 cases. CGH array-based studies identified deletion polymorphisms within a putative regulatory enhancer of FAT1, predictive of tissue-specific depletion of FAT1 expression, which preferentially segregate with FSHD. Our study identifies FAT1 as a critical determinant of muscle form, misregulation of which associates with FSHD