Functional analysis of germline VANGL2 variants using rescue assays of vangl2 knockout zebrafish

Abstract Developmental studies have shown that the evolutionarily conserved Wnt Planar Cell Polarity (PCP) pathway is essential for the development of a diverse range of tissues and organs including the brain, spinal cord, heart and sensory organs, as well as establishment of the left-right body axis. Germline mutations in the highly conserved PCP gene VANGL2 in humans have only been associated with central nervous system malformations, and functional testing to understand variant impact has not been performed. Here we report three new families with missense variants in VANGL2 associated with heterotaxy and congenital heart disease p.(Arg169His), non-syndromic hearing loss p.(Glu465Ala) and congenital heart disease with brain defects p.(Arg135Trp). To test the in vivo impact of these and previously described variants, we have established clinically-relevant assays using mRNA rescue of the vangl2 mutant zebrafish. We show that all variants disrupt Vangl2 function, although to different extents and depending on the developmental process. We also begin to identify that different VANGL2 missense variants may be haploinsufficient and discuss evidence in support of pathogenicity. Together, this study demonstrates that zebrafish present a suitable pipeline to investigate variants of unknown significance and suggests new avenues for investigation of the different developmental contexts of VANGL2 function that are clinically meaningful.

. Supplemental information relating VANGL2 VUS in Tables 1 and 2 Family

Table S2 .
Statistical tests relating to Figure4K.AP length compared to uninjected vangl2 m209Brown-Forsythe and Welch ANOVA with multiple comparisons

Table S5 .
Statistical tests relating to Figure 6C.

Table S6 .
Statistical tests relating to Figure 7C.

Table S7 .
Statistical tests relating to Figure 7E.

Table S8 .
Primers for site mutagenesis of the WT VANGL2 plasmid