Choroideremia Treatment in Uganda

The opening sign is almost always night blindness that starts in childhood, well ahead of any other change. From there, the field of vision narrows steadily across the teenage years and into adult life. The feature that really distinguishes choroideremia is just how long central vision manages to survive — commonly for several decades longer than in most other inherited retinal diseases — though it isn’t permanent, and can eventually be lost once the degeneration reaches the macula in mid-to-late adulthood.

The culprit is the CHM gene, carried on the X chromosome, and its loss means cells across the choroid, RPE, and photoreceptor layers run short of a protein called REP1 that they need to keep functioning. Because it’s X-linked, a mother who carries the mutation passes it to roughly half her sons, who go on to be affected, and to roughly half her daughters, who become carriers in turn.

On fundus examination, choroideremia tends to produce a fairly recognisable scalloped appearance as the choroid and RPE waste away, and paired with electroretinography and OCT scans, that pattern is usually enough to set it apart from other rod-cone dystrophies at a fairly early stage. Genetic testing for CHM mutations settles the question definitively, and is particularly valuable for checking carrier status in female relatives.