多指和并指是先天性肢体畸形,以常染色体显性方式分离。GLI3基因的变异与先天性肢体畸形密切相关。然而,多指和齐指的根本原因还没有得到很好的理解。
我们对两个多指和并指的四代中国家庭进行了全外显子组测序。然后将c.2374C>T和c.1728C>A突变质粒转染至HEK293T细胞和小鼠肢芽细胞以探索这些变体的功能后果。采用Westernblot和实时定量PCR方法分析GLI3和Shh的表达。
在这两个家庭中,已知的GLI3变体(NM_000168.6:c.2374C>T)和新颖的GLI3变体(NM_000168.6:c.1728C>A)促成了多指和合成。此外,GLI3c.2374C>T突变质粒导致GLI3蛋白截短,GLI3c.1728C>A突变质粒导致降解GLI3蛋白。同时,我们证明GLI3突变质粒导致小鼠肢芽细胞中Shh表达降低。
我们证明了新的GLI3变体(c.1728C>A)和已知的GLI3变体(c.2374C>T)通过影响SHH信号传导而导致了两个四代谱系的畸形,具有多指和连指。
Polydactyly and syndactyly are congenital limb deformities, segregating in an autosomal-dominant fashion. The variants in the
GLI3 gene are closely related to congenital limb malformations. However, the causes underlying polydactyly and syndactyly are not well understood.
We conducted a whole-exome sequencing on two four-generation Chinese families with polydactyly and syndactyly. Then c.2374C>T and c.1728C>A mutant plasmids were transfected to HEK293T cells and mice limb bud cells to explore the functional consequences of these variants. Western blot and real-time quantitative PCR were used to analyze the expression of GLI3 and Shh.
In these two families, the known
GLI3 variant (NM_000168.6:c.2374C>T) and the novel
GLI3 variant (NM_000168.6:c.1728C>A) contributed to polydactyly and syndactyly. Additionally, the
GLI3 c.2374C>T mutant plasmid led to truncated
GLI3 protein, and the
GLI3 c.1728C>A mutant plasmid led to degraded
GLI3 protein. Simultaneously, we demonstrated that the GLI3-mutant plasmids led to decreased Shh expression in mice limb bud cells.
We demonstrated that the novel
GLI3 variant (c.1728C>A) and known
GLI3 variant (c.2374C>T) contributed to the malformations in two four-generation pedigrees with polydactyly and syndactyly by affecting SHH signaling.