Fit ofELA2mutations into one of three proposed functional categories.

The linear sequence of the protein is marked with respect to the processed pre-pro amino and carboxyl termini, predicted transmembrane domains (TM-1 and TM-2), cryptic transmembrane (TM-cryptic) domain predicted as a result of some mutations, and proposed recognition site of the AP3 mu subunit. Squares represent mutations exclusively causing severe congenital neutropenia (SCN). Circles indicate mutations found in cyclic neutropenia patients (but that may also appear in SCN patients). Horizontal lines depict deletions. Lines connected by right angles reveal disulfide bonds that generally bracket predicted transmembrane domains, with mutated cysteine residues at their corners. Missense mutations generally aligning with transmembrane domains are colored black. Mutations destroying disulfide bonds are shaded light gray. Chain terminating nonsense and frameshift mutations that delete the AP3 mu recognition signal are shaded dark gray. Each mutation, compiled from reference ¹⁰ and the author’s unpublished data, is shown once. Mutations unaccounted for by this classification scheme are listed in the text, but not charted.