BACKGROUND The Xp22.11 locus that encompasses PTCHD1, DDX53, and the long noncoding RNA PTCHD1-AS is frequently disrupted in male subjects with autism spectrum disorder (ASD), but the functional consequences of these genetic risk factors for ASD are unknown. METHODS To evaluate the functional consequences of PTCHD1 locus deletions, we generated induced pluripotent stem cells (iPSCs) from unaffected control subjects and 3 subjects with ASD with microdeletions affecting PTCHD1-AS/PTCHD1, PTCHD1-AS/DDX53, or PTCHD1-AS alone. Function of iPSC-derived cortical neurons was assessed using molecular approaches and electrophysiology. We also compiled novel and known genetic variants of the PTCHD1 locus to explore the roles of PTCHD1 and PTCHD1-AS in genetic risk for ASD and other neurodevelopmental disorders. Finally, genome editing was used to explore the functional consequences of deleting a single conserved exon of PTCHD1-AS. RESULTS iPSC-derived neurons from subjects with ASD exhibited reduced miniature excitatory postsynaptic current frequency and N-methyl-D-aspartate receptor hypofunction. We found that 35 ASD-associated deletions mapping to the PTCHD1 locus disrupted exons of PTCHD1-AS. We also found a novel ASD-associated deletion of PTCHD1-AS exon 3 and showed that exon 3 loss altered PTCHD1-AS splicing without affecting expression of the neighboring PTCHD1 coding gene. Finally, targeted disruption of PTCHD1-AS exon 3 recapitulated diminished miniature excitatory postsynaptic current frequency, supporting a role for the long noncoding RNA in the etiology of ASD. CONCLUSIONS Our genetic findings provide strong evidence that PTCHD1-AS deletions are risk factors for ASD, and human iPSC-derived neurons implicate these deletions in the neurophysiology of excitatory synapses and in ASD-associated synaptic impairment.

中文翻译：

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PTCHD1-AS 自闭症相关缺失的人类神经元突触功能障碍

背景 包含 PTCHD1、DDX53 和长链非编码 RNA PTCHD1-AS 的 Xp22.11 基因座在患有自闭症谱系障碍 (ASD) 的男性受试者中经常被破坏，但这些遗传风险因素对 ASD 的功能后果尚不清楚。方法 为了评估 PTCHD1 基因座缺失的功能后果，我们从未受影响的对照受试者和 3 名患有 ASD 的受试者中产生诱导多能干细胞 (iPSC)，这些受试者的微缺失影响 PTCHD1-AS/PTCHD1、PTCHD1-AS/DDX53 或单独的 PTCHD1-AS。使用分子方法和电生理学评估 iPSC 衍生的皮层神经元的功能。我们还汇编了 PTCHD1 基因座的新的和已知的遗传变体，以探索 PTCHD1 和 PTCHD1-AS 在 ASD 和其他神经发育障碍的遗传风险中的作用。最后，基因组编辑用于探索删除 PTCHD1-AS 的单个保守外显子的功能后果。结果 来自 ASD 受试者的 iPSC 衍生神经元表现出降低的微型兴奋性突触后电流频率和 N-甲基-D-天冬氨酸受体功能减退。我们发现映射到 PTCHD1 基因座的 35 个 ASD 相关缺失破坏了 PTCHD1-AS 的外显子。我们还发现了一种新的 ASD 相关的 PTCHD1-AS 外显子 3 缺失，并表明外显子 3 缺失改变了 PTCHD1-AS 剪接而不影响相邻 PTCHD1 编码基因的表达。最后，PTCHD1-AS 外显子 3 的靶向破坏概括了减少的微型兴奋性突触后电流频率，支持长非编码 RNA 在 ASD 病因学中的作用。