choroideremia

Choroideremia is an X-linked chorioretinal dystrophy that primarily affects the eyes, leading to progressive degeneration of the choroid, retinal pigment epithelium, and retina. This condition is caused by pathogenic variants in the CHM gene, which is essential for cellular processes within the retina. It predominantly affects males, with affected female carriers often experiencing milder symptoms due to variable X-inactivation. The condition is considered uncommon, affecting roughly 1 to 9 individuals per 100,000, and its presentation typically unfolds over several decades.

The clinical presentation of choroideremia centers on progressive visual disturbances. Nearly all affected individuals experience night blindness (nyctalopia), a constriction of their peripheral visual field, pigmentary retinopathy, and progressive visual loss. Additional features observed in a subset of patients include the presence of bone spicule pigmentation, attenuation of retinal blood vessels, a granular macular appearance, nummular pigmentation of the fundus, and retinal pigment epithelial mottling. Not all individuals experience every feature, and severity varies considerably between affected persons.

Choroideremia is caused by mutations in the CHM gene, which encodes a protein that plays a key role in intracellular vesicular trafficking within retinal cells. The disruption of this protein impairs normal cellular maintenance and leads to the gradual degeneration of the choroid, retinal pigment epithelium, and retina. The condition follows an X-linked inheritance pattern, meaning that affected males typically manifest the full spectrum of symptoms while female carriers may have a milder presentation due to skewed X-inactivation. Families are encouraged to seek genetic counseling to explore implications for family planning and understand their individual recurrence risks.

Currently, management of choroideremia focuses on supportive care and symptom management, as there are no treatments that have completed the FDA review for this condition. Patients are managed through a multidisciplinary approach, and regular surveillance is an essential part of long-term care, helping to identify potential complications at an early stage. Although no foundational therapies are linked to choroideremia at this time, several investigational treatments are under development, and a number of clinical trials are exploring new treatment approaches. Genetic counseling is recommended, and patients should discuss available supportive options with their healthcare team to tailor treatment to their individual needs.

The clinical course of choroideremia is highly variable, with many individuals experiencing a gradual loss of vision over time. While the condition is progressive, outcomes depend on symptom severity, age at diagnosis, and access to supportive care, making each patient’s trajectory unique. With current standards of care and regular monitoring, many affected individuals maintain functional vision into adulthood, though progressive visual field loss is common. Outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with specialists, such as ophthalmologists and genetic counselors, to gain personalized insights and support for long-term management.

Choroideremia is an active area of research with several clinical trials currently investigating new treatment approaches. Individuals interested in learning more about emerging therapies or participating in research can search ClinicalTrials.gov or consult their care team regarding potential eligibility.