手/足分裂畸形(SHFM)是一种罕见的肢体异常,手指和/或脚趾裂开。对很多人来说,遗传病因不明。通过全外显子组和靶向测序,我们在编码转录因子的基因中检测到三个新的变异,PRDM1,在SHFM家族中从头出现或与表型分离。PRDM1是肢体发育所必需的;然而,其作用尚不清楚,也不清楚PRDM1变体如何影响蛋白质功能.在斑马鱼中使用瞬时和稳定的过表达拯救实验,我们表明,变体破坏脯氨酸/丝氨酸丰富和DNA结合锌指结构域,导致显性负效应。通过基因表达测定,RNA测序,在分离的胸鳍细胞中进行CUT和RUN,我们证明Prdm1a直接结合并调节鳍诱导所需的基因,生长和前/后图案,如fgfr1a,dlx5a,dlx6a和smo.一起来看,这些结果提高了我们对PRDM1在肢体基因调控网络中的作用的理解,并鉴定了与人类SHFM相关的新型PRDM1变异体.
Split hand/foot malformation (SHFM) is a rare limb abnormality with clefting of the fingers and/or toes. For many individuals, the genetic etiology is unknown. Through whole-exome and targeted sequencing, we detected three novel variants in a gene encoding a transcription factor, PRDM1, that arose de novo in families with SHFM or segregated with the phenotype. PRDM1 is required for limb development; however, its role is not well understood and it is unclear how the PRDM1 variants affect protein function. Using transient and stable overexpression rescue experiments in zebrafish, we show that the variants disrupt the proline/serine-rich and DNA-binding zinc finger domains, resulting in a dominant-negative effect. Through gene expression assays, RNA sequencing, and CUT&RUN in isolated pectoral fin cells, we demonstrate that Prdm1a directly binds to and regulates genes required for fin induction, outgrowth and anterior/posterior patterning, such as fgfr1a, dlx5a, dlx6a and smo. Taken together, these results improve our understanding of the role of PRDM1 in the limb gene regulatory network and identified novel PRDM1 variants that link to SHFM in humans.