Table of Contents
Bardet-Biedl Syndrome
Main Features
- Dysfunction of Brain, eye, kidneys and genitalia
Eye Findings
- Retinal degeneration (almost 100%)
- Rod-cone dystrophy with early macular involvement
- Pigmentary changes in macula first
- ERG
- Symptoms in order of presentation
- Nyctalopia age 4-8 years
- Progressive peripheral vision loss
- Decline of color vision
- Legal blindness by 20-30 years old
- Strabismus
- Cataracts
- Astigmatism
Bardet-Biedl Syndrome Retinopathy Clinical Grading System
| Grade | Description | Subtypes | Clinical Features |
|---|---|---|---|
| 0 | Normal | None | |
| 1 | Preclinical Retinopathy | No fundoscopic evidence of retinopathy but evidence of reduced visual function (acuity, visual fields, ERG) | |
| 2 | Clinical Retinopathy | 2c | Central disease with foveal atrophy |
| 2p | Peripheral disease with pigmentary reinopathy | ||
| 2g | Global disease with central and peripheral involvement but no features of stage 3 | ||
| 3 | End-stage retinopathy | Advanced central and peripheral involvement, which may include extensive scarring, vascular attenuation, choroidal atrophy, and significant disc pallor |
Adapted from Dennison AK et al. Retina 2014;34:2282-2289
Other Findings
- Obesity
- Postaxial polydactyly
- Renal anomalies
- Learning disability
- Hypogonadism and Genitourinary abnormalities
- Cardiac defects
From resource 1 below
Etiology
- Non-motile ciliopathy- dysfunction of the primary cilium.
- Autosomal Recessive