Fig. 1

Screening and preliminary prediction of the candidate gene. A Pedigree of the index family. B Flowchart of the variant filtering process. C Simplified structure chart of human protein FMN2 (1722aa). N = N-terminus, C = C-terminal tail. Major functional regions FH1, FH2 are colored in red, nuclear localization sequence 1 and 2 (NLS1, NLS2) are colored in orange and green respectively, spire-binding regions are marked with blue, and the black arrow points to the mutation sites. D Sanger sequencing results of p.650 in the family case. E Cross-species alignment of FMN2. □ denotes p.650 site in FMN2 proteins, which is serine in 9 primates. F Simplified 3D Cartoon models for human FMN2 protein. The mutant sites were colored in red, FH2 domains were colored in green, while other residues were colored in blue. MT mutant type; WT wild type