Choroideremia.

PURPOSE OF REVIEW: Although much has been written to define the phenotype and genotype of choroideremia (CHM), research continues to provide new insights that serve to better understand its pathogenesis and the directions for potential experimental therapies. RECENT FINDINGS: We would like to highlight new findings, expanding the type of disease-causing mutations to include mutations in the CHM promoter that will dramatically influence gene expression. Information derived from careful phenotyping of patients points increasingly to the central role of the retinal pigment epithelium as the key cell layer affected in the degenerative process. Finally, we will review the current initiatives that are testing vector-mediated gene replacement approaches in humans, including our current understanding of the likelihood of success by this approach. SUMMARY: Clinical and basic vision science have benefited greatly by the active engagement of patients with CHM in clinical research studies. The impetus for their involvement in these studies has been generated by the initial results of safety from subretinal injection of and AAV2.REP1 vector in humans. Follow-up studies in the next few years are expected to show if this approach will modify disease progression.