Positions of known mutations in the genes for GFI1 and GFI1B. Shown is a summary of the consequences of the known inherited and congenital mutations in the human GFIB gene (upper) and the human GFI1 gene (lower) for their respective protein sequences. All mutations in the GFI1B gene are associated with platelet disorders, and the mutations in the GFI1 gene are associated with SCN.