Overview
Familial drusen encompasses several autosomal dominant conditions with early-onset drusen formation at the macula, including Doyne honeycomb retinal dystrophy (EFEMP1 Arg345Trp), dominant drusen (C1QTNF5/CTRP5), and late-onset retinal degeneration (C1QTNF5). These conditions share drusen accumulation in Bruch's membrane with risk of choroidal neovascularization and geographic atrophy, closely mimicking age-related macular degeneration but with earlier onset and identifiable genetic causes.
Genetics
Multiple causative genes. EFEMP1 causes Doyne honeycomb. C1QTNF5 causes dominant drusen and late-onset retinal degeneration (L-ORD). All autosomal dominant.
| Gene | Locus | Inheritance | Notes |
|---|---|---|---|
| EFEMP1 | 2p16.1 | AD | Arg345Trp founder mutation; Doyne honeycomb / Malattia Leventinese |
| C1QTNF5 (CTRP5) | 11q23.3 | AD | Complement C1q tumor necrosis factor-related protein 5; dominant drusen and L-ORD |
Clinical Presentation
3rd–5th decade
- Drusen deposits at macula
- Mild visual distortion
- Gradual visual acuity reduction
Progressive
- Geographic atrophy
- Choroidal neovascularization
- Significant central vision loss
Diagnosis
- Fundus: Early-onset drusen, often with family history
- OCT: Drusen, RPE atrophy
- Genetic testing: EFEMP1, C1QTNF5 sequencing
- Fluorescein angiography: CNV if present
Current Research & Treatment
Anti-VEGF for CNV. Complement pathway inhibitors being studied. These conditions serve as models for AMD research.
Active Clinical Trials
The following active clinical trials are investigating treatments for Familial Drusen (Malattia Leventinese / Doyne Honeycomb). Trial status and enrollment may change; always verify directly on ClinicalTrials.gov.