Short answer · Medically reviewed summary · Last updated: 2026-05-08
TL;DR: Choroideremia is a rare, X-linked genetic disorder that causes progressive vision loss due to the degeneration of the retina and the underlying choroid blood vessel layer. While it primarily affects males, it leads to a gradual narrowing of the visual field and night blindness, eventually progressing to total blindness in many individuals. What is Choroideremia and how does it affect the body? Choroideremia is a rare, inherited condition that specifically targets the eyes.
What is Choroideremia
What is Choroideremia? Plain-language, medically reviewed definition plus the lived reality told by patients.
TL;DR: Choroideremia is a rare, X-linked genetic disorder that causes progressive vision loss due to the degeneration of the retina and the underlying choroid blood vessel layer. While it primarily affects males, it leads to a gradual narrowing of the visual field and night blindness, eventually progressing to total blindness in many individuals.
What is Choroideremia and how does it affect the body?
Choroideremia is a rare, inherited condition that specifically targets the eyes. It causes the progressive atrophy of the choroid (the vascular layer behind the retina), the retinal pigment epithelium, and the photoreceptor cells. As these tissues degenerate, individuals with Choroideremia typically experience a transition from initial night blindness to a significant loss of peripheral vision, often referred to as "tunnel vision."
Who is typically affected by Choroideremia?
Because Choroideremia is an X-linked recessive disorder, it almost exclusively affects males. While females are typically asymptomatic carriers, they may occasionally show mild retinal changes. The prevalence of Choroideremia is estimated to be between 1 in 50,000 and 1 in 100,000 individuals globally. Symptoms usually begin in late childhood or adolescence, though the rate of progression can vary significantly even within the same family.
What causes Choroideremia?
The underlying cause of Choroideremia is a mutation in the CHM gene, which provides instructions for producing a protein called Rab escort protein-1 (REP-1). This protein is essential for the transport of molecules within cells. When the CHM gene is mutated, the lack of functional REP-1 leads to the premature death of light-sensing cells in the eye.
Key facts that differentiate Choroideremia
- Genetic Pattern: It follows an X-linked inheritance pattern, meaning mothers can pass the gene to their sons.
- Visual Progression: Unlike some other retinal dystrophies, Choroideremia involves the loss of both the photoreceptors and the underlying blood supply (the choroid).
- Community Insight: Currently, 96 people with Choroideremia have joined the DiseaseMaps community to share their experiences and support one another.
Next steps
- Schedule a comprehensive evaluation with a retinal specialist or an ophthalmologist experienced in genetic eye diseases.
- Undergo genetic testing to confirm the specific CHM mutation, which is vital for clinical trial eligibility.
- Connect with the 96 members of the DiseaseMaps community to share resources and coping strategies.
- Stay informed about emerging gene therapy research by visiting sites like the Foundation Fighting Blindness.
Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment; always seek the advice of your physician regarding any medical condition.
References
- NIH Genetic and Rare Diseases Information Center (GARD): Choroideremia
- Orphanet: Choroideremia (ORPHA:167)
- Online Mendelian Inheritance in Man (OMIM): #303100
- Foundation Fighting Blindness: Understanding Choroideremia
