Vasterbotten dystrophy

Retinal Dystrophy, Bothnia Type

Clinical Characteristics
Ocular Features: 

Night blindness occurs from early childhood when the fundus still appears normal.  However, rod responses may be absent from ERG recordings even in the first decade and this is followed by loss of cone responses in older individuals. Rod responses can recover after prolonged dark adaptation but cone function does not recover.  Multifocal ERGs can detect early deterioration of the macula while vision and the appearance of the macula are still normal.

Pigment deposition can sometimes be seen in the retina and the retinal blood vessels may be attenuated.  In young adults the fundus may have the appearance of retinitis albescens but eventually changes resembling central areolar atrophy develop in the macula.  Retinal thinning in the fovea and parafoveal areas has been described.  Progressive loss of vision leads to legal blindness in early adulthood.  The peripheral retina undergoes degenerative changes as well.

Systemic Features: 

No extraocular abnormalities have been reported.

Genetics

Homozygous mutations in the RLBP1 gene (15q26.1) have been identified in patients with Bothnia retinal dystrophy.  The protein product is essential to the proper function of both rod and cone photoreceptors.  When defective the normal cycling of retinoids between RPE cells and photoreceptors is disrupted, thereby negatively impacting what is sometimes called the 'visual cycle'. 

This rod-cone dystrophy has a high prevalence in northern Sweden.

Homozygous mutations in RLBP1 have also been found among patients in fundus albipunctatus (136880), retinitis punctata albescens, and in Newfoundland type retinal dystrophy (607476).

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

None has been reported. Tinted lenses can be helpful.

References
Article Title: 
Subscribe to RSS - Vasterbotten dystrophy