两种罕见角膜基质营养不良的临床病理特征和分子遗传学研究

发布时间：2018-03-15 00:08

  本文选题：角膜营养不良　切入点：TACSTD2基因　出处：《郑州大学》2010年博士论文　论文类型：学位论文

【摘要】： 目的：观察胶样滴状角膜营养不良和施奈德角膜营养不良这两种罕见的角膜基质营养不良的临床表现,研究患者角膜组织病理学及活体角膜共焦显微镜和眼前节光学断层扫描的图像特征,同时分析胶样滴状角膜营养不良致病基因TACSTD2基因和施奈德角膜营养不良致病基因UBIAD1基因的突变情况,研究这两种角膜基质营养不良的分子遗传学机制。 方法：收集独立的胶样滴状角膜营养不良家系3个和施奈德角膜营养不良家系1个,对4个家系中的4例角膜营养不良患者行以新鲜角膜作为供体的深板层角膜移植术,将患者病变角膜组织做病理组织学、透射及扫描电镜检查,并在术前对患者角膜分别进行裂隙灯拍照、活体共焦显微镜和眼前节光学相干断层扫描,同时从患病者及其家系成员的外周静脉血中提取基因组DNA,用特异性引物分别将致病基因TACSTD2和UBIAD1基因行PCR扩增,PCR产物纯化后进行双向测序,设50例正常人作为对照,分析患者基因型的改变。 结果：胶样滴状角膜营养不良患者角膜表面可以见到呈半球形隆起的灰白色胶滴状结节；病变角膜片在刚果红染色下显示特征性的角膜上皮下红染的淀粉样物质沉积,累及前部角膜基质,角膜上皮基底膜和前弹力层结构消失；扫描电镜下可见角膜表层上皮细胞之间间隙增大,透射电镜下可见角膜上皮基底细胞的基底面出现大量钉突状突起结构并向下插入其下的淀粉样沉积物中,沉积物的超微结构呈典型的淀粉样纤维外观；活体共焦显微镜检查见患者角膜表层上皮细胞间连接异常,细胞间有较大间隙,上皮基底细胞层次不清、胞体肿胀,上皮基底细胞层下可见无定形的高反光物质沉积,累及前部基质；在眼前节光学相干断层扫描图像上,患者的角膜病变主要位于上皮细胞层和前部基质,角膜表面凹凸不平,呈波浪样,角膜基质的胶原板层规则排列被破坏,基质内呈强弱不一致的回声信号。施奈德角膜营养不良结晶型患者右眼角膜中央区基质层混浊,角膜上皮下有散在点状结晶,左眼角膜中轴部的前基质层内有一环形或边缘不规整的、略呈盘状的黄白色混浊,混浊由无数细小、针状结晶组成；施奈德角膜营养不良无结晶型患者可见双眼角膜中轴部可见一无结晶圆盘状混浊；透射电镜下可见角膜基质浅层与Bowman层中有胆固醇结晶沉积；活体共焦显微镜检查见结晶型患者角膜前弹力层及浅基质层内可见到大量点状、散在分布的结晶物,无结晶型患者则未见到针状或方形的胆固醇结晶物质存在于角膜组织内；在眼前节光学相干断层扫描图像上,施奈德角膜营养不良患者的角膜病变主要位于前部基质,显示为高信号强度的致密物质。分子遗传学的研究发现3个胶样滴状角膜营养不良家系的患者TACSTD2基因分别出现c.526 576de151、C.509CA和c.356GA突变。在患者中突变以纯合子存在,在患者父母和其他未患病的亲属中以杂合子存在,50例正常对照者中未发现TACSTD2基因突变；施奈德角膜营养不良家系的患者UBIAD1基因出现c.292 GA突变,在患者中突变以杂合子存在,50例正常对照者中未发现UBIAD1基因突变。 结论：胶样滴状角膜营养不良特征性的临床表现是角膜表面颗粒状隆起物伴基质混浊,病理组织学特征是角膜上皮下的淀粉样物质沉积；施奈德角膜营养不良具有结晶型和非结晶型两种临床表现,病理组织学特征是角膜基质内的胆固醇结晶物沉积；我们首次报道了胶样滴状角膜营养不良和施奈德角膜营养不良的活体共焦显微镜及眼前节相干光学断层扫描图像特征,这两种检查可发现角膜营养不良角膜内异常物质的沉积和细胞结构的改变,在疾病的随访和手术疗效评估中有重要意义；分子遗传学的研究发现胶样滴状角膜营养不良和施奈德角膜营养家系的患者分别呈现TACSTD2和UBIAD1基因突变,基因突变分析为疾病的确诊提供可靠的依据并有助于对这两种罕见角膜基质营养不良发病机制的进一步认识。
[Abstract]:Objective: To observe the gelatinous drop like corneal dystrophy and Schneider corneal dystrophy of the two rare corneal stromal dystrophy clinical manifestation, image characteristics and in vivo confocal microscopy and anterior segment optical tomography corneal tissue of patients with pathological study, mutation analysis of UBIAD1 gene of colloid droplet corneal dystrophy gene TACSTD2 gene and Schneider corneal dystrophy genes at the same time, study the two kinds of corneal dystrophy molecular mechanism.
Methods: collect separate colloid droplets of corneal dystrophies and Schneider 3 corneal dystrophies 1, of 4 families in 4 cases of corneal dystrophy patients with fresh corneal as deep lamellar keratoplasty donor, the lesions in patients with corneal tissue pathological histology. Transmission and scanning electron microscopy, and in preoperative patients cornea were examined by slit lamp photograph, coherence tomography in vivo confocal microscopy and anterior segment optical, genomic DNA was extracted from peripheral venous blood from patients and their family members, using specific primers respectively will TACSTD2 gene and UBIAD1 gene amplified by PCR and the purified PCR products were sequenced, 50 cases of normal people as control, analysis of the patient's genotype.
Results: the colloid droplet corneal dystrophy corneal surface can see a white gelatinous drop like nodules hemispherical bulge; corneal lesions showed amyloid deposition characteristics of corneal subepithelial red stained with Congo red staining, involving the anterior corneal stroma, corneal epithelial basement membrane disappeared and Bowman structure; scanning electron microscope showed that the corneal surface between the epithelial cell gap increased, visible basal corneal epithelial basal cells surface under transmission electron microscopy, the emergence of a large number of spike like protrusions and down into amyloid deposits under it, the ultrastructure of sediments showed the typical appearance of amyloid fibrils; in vivo confocal microscopy in patients with corneal epithelial surface. The connection between abnormal cells, intercellular large gap, epithelial basal cells and poorly, cell body swelling, epithelial basal cell layer showed amorphous high reflective 鐗╄川娌夌Н,绱�鍙婂墠閮ㄥ熀璐�锛涘湪鐪煎墠鑺傚厜瀛︾浉骞叉柇灞傛壂鎻忓浘鍍忎笂,鎮ｈ，

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