To report newly found TSPAN12 mutations with a unique form of familial exudative vitreoretinopathy (FEVR) and find out the possible mechanism of a repeated novel intronic variant in TSPAN12 led to FEVR. Nine TSPAN12 mutations with a unique form of FEVR were detected by panel-based NGS. MINI-Gene assay showed two splicing modes of mRNA that process two different bands A and B, and mutant-type shows replacement with the splicing mode of Exon11 hopping. Construction of wild-type and mutant TSPAN12 vector showed the appearance of premature termination codons (PTC). In vitro expression detection showed significant down-regulated expression level of TSPAN12 mRNAs and proteins in cells transfected with mutant vectors compared with in wild-type group. On the contrary, translation inhibitor CHX and small interfering RNA of UPF1 (si-UPF1) significantly increased mRNA or protein expression of TSPAN12 in cells transfected with the mutant vectors. Nine mutations in TSPAN12 gene are reported in 9 FEVR patients with a unique series of ocular abnormalities. The three novel TSPAN12 mutations trigger NMD would cause the decrease of TSPAN12 proteins that participate in biosynthesis and assembly of microfibers, which might lead to FEVR, and suggest that intronic sequence analysis might be a vital tool for genetic counseling and prenatal diagnoses.

中文翻译：

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TSPAN12基因突变导致家族性渗出性玻璃体视网膜病变

报告新发现的 TSPAN12 突变与家族性渗出性玻璃体视网膜病变 (FEVR) 的独特形式，并找出 TSPAN12 中重复的新型内含子变异导致 FEVR 的可能机制。基于组合的 NGS 检测到了 9 种具有独特形式 FEVR 的 TSPAN12 突变。MINI-Gene检测显示mRNA的两种剪接模式分别处理两个不同的条带A和B，突变型显示与Exon11跳跃的剪接模式的替代。野生型和突变型 TSPAN12 载体的构建显示出过早终止密码子 (PTC) 的出现。体外表达检测显示，与野生型组相比，突变载体转染的细胞中TSPAN12 mRNA和蛋白的表达水平显着下调。相反，翻译抑制剂CHX和UPF1的小干扰RNA(si-UPF1)显着增加了用突变载体转染的细胞中TSPAN12的mRNA或蛋白表达。据报道，9 名具有一系列独特眼部异常的 FEVR 患者存在 TSPAN12 基因的 9 种突变。触发NMD的三个新的TSPAN12突变会导致参与微纤维生物合成和组装的TSPAN12蛋白减少，这可能导致FEVR，并表明内含子序列分析可能是遗传咨询和产前诊断的重要工具。