Congenital heart disease (CHD) associated with polydactyly involves various genes. We aimed to identify variations from genes related to complex CHD with polydactyly and to investigate the cellular functions related to the mutations. Blood was collected from a complex CHD case with polydactyly, and whole exome sequencing (WES) was performed. The CRISPR/Cas9 system was used to generate human pluripotent stem cell with mutations (hPSCs‐Mut) that were differentiated into cardiomyocytes (hPSC‐CMs‐Mut) and analysed by transcriptomics on day 0, 9 and 13. Two heterozygous mutations, LTBP2 (c.2206G>A, p.Asp736Asn, RefSeq NM_000428.2) and TCTN3 (c.1268G>A, p.Gly423Glu, RefSeq NM_015631.5), were identified via WES but no TBX5 mutations were found. The stable cell lines of hPSCs‐LTBP2^mu/TCTN3^mu were constructed and differentiated into hPSC‐CMs‐LTBP2^mu/TCTN3^mu. Compared to the wild type, LTBP2 mutation delayed the development of CMs. The TCTN3 mutation consistently presented lower rate and weaker force of the contraction of CMs. For gene expression pattern of persistent up‐regulation, pathways in cardiac development and congenital heart disease were enriched in hPSCs‐CM‐LTBP2^mu, compared with hPSCs‐CM‐WT. Thus, the heterozygous mutations in TCTN3 and LTBP2 affect contractility (rate and force) of cardiac myocytes and may affect the development of the heart. These findings provide new insights into the pathogenesis of complex CHD with polydactyly.

中文翻译：

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TCTN3/LTBP2 的新突变与多指畸形相关先天性心脏病的细胞功能变化

与多指畸形相关的先天性心脏病 (CHD) 涉及多种基因。我们的目的是识别与多指畸形复杂冠心病相关基因的变异，并研究与突变相关的细胞功能。从患有多指畸形的复杂 CHD 病例中采集血液，并进行全外显子组测序 (WES)。CRISPR/Cas9 系统用于生成具有突变的人类多能干细胞 (hPSCs-Mut)，这些突变分化为心肌细胞 (hPSC-CMs-Mut)，并在第 0、9 和 13 天通过转录组学分析。两个杂合突变，LTBP2 ( c.2206G>A, p.Asp736Asn, RefSeq NM_000428.2) 和 TCTN3 (c.1268G>A, p.Gly423Glu, RefSeq NM_015631.5) 通过 WES 鉴定，但未发现 TBX5 突变。^{hPSCs-LTBP2 mu} /TCTN3 ^mu稳定细胞系构建并分化为hPSC-CMs- ^LTBP2μ / ^TCTN3μ。与野生型相比，LTBP2 突变延迟了 CM 的发展。TCTN3 突变始终表现出较低的 CM 收缩率和较弱的收缩力。对于持续上调的基因表达模式，与 hPSCs-CM-WT 相比，hPSCs- CM-LTBP2 ^mu中丰富了心脏发育和先天性心脏病的途径。因此，TCTN3 和 LTBP2 的杂合突变影响心肌细胞的收缩力（速率和力），并可能影响心脏的发育。这些发现为复杂多指先心病的发病机制提供了新的见解。