FIGURE 6.

Disease-causing mutations in ELOVL4. STGD3-causing mutations (blue) result in early truncation of ELOVL4 and the loss of the C-terminal ER retention motif or, in the case of the promoter mutations, severely suppress ELOVL4 expression. SCA34-causing mutations (green) result in amino acid substitutions but still produce a full-length protein. ELOVL4 Neuro-ichthyosis-causing mutations (red) cause very early termination of the protein that would truncate substantial portions of transmembrane domains in either the 5-transmembrane or 7-transmembrane models of ELOVL4 topology in addition to deleting the ER retention motif.