Genetic variation in the highly conserved Sonic Hedgehog (SHH) gene is one of the most common genetic causes for the malformations of the brain and face in humans described as the holoprosencephaly clinical spectrum. However, only a minor fraction of known SHH variants have been experimentally proven to lead to abnormal function. Employing a phenotypic rescue assay with synthetic human messenger RNA variant constructs in shha^−/− knockout zebrafish, we evaluated 104 clinically reported in‐frame and missense SHH variants. Our data helped us to classify them into loss of function variants (31), hypomorphic variants (33), and nonpathogenic variants (40). We discuss the strengths and weaknesses of currently accepted predictors of variant deleteriousness and the American College of Medical Genetics and Genomics guidelines for variant interpretation in the context of this functional model; furthermore, we demonstrate the robustness of model systems such as zebrafish as a rapid method to resolve variants of uncertain significance.

中文翻译：

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使用 CRISPR/Cas9 斑马鱼模型对与人类全前脑畸形相关的 Sonic Hedgehog 变体进行功能分析。

高度保守的Sonic Hedgehog ( SHH ) 基因的遗传变异是人类大脑和面部畸形的最常见遗传原因之一，被描述为全前脑畸形临床谱。然而，只有一小部分已知的SHH变体被实验证明会导致功能异常。在shha ^-/-敲除斑马鱼中使用合成人类信使 RNA 变体构建体进行表型拯救分析，我们评估了 104 条临床报告的框内和错义SHH变种。我们的数据帮助我们将它们分类为功能缺失变异 (31)、亚形变异 (33) 和非致病变异 (40)。我们在此功能模型的背景下讨论了目前公认的变异有害预测因子的优缺点以及美国医学遗传学和基因组学学院关于变异解释的指南；此外，我们证明了模型系统（如斑马鱼）的稳健性，作为解决不确定意义的变体的快速方法。