FZD6 and Nail dysplasia: For example, it was observed that Fzd6 signalling activates β-catenin in a study of patients affected by nail dysplasia caused by germline FZD6 mutations.21 This study reported that wnt3a signalling causes β-catenin accumulation in healthy, but not FZD6-mutant, fibroblasts, indicating a canonical role of Fzd6 in this context.