Retinal Dystrophy, Newfoundland Type

Clinical Characteristics
Ocular Features: 

There is considerable clinical heterogeneity, mostly age-dependent.  Night blindness can occur in early childhood but usually later even though scotopic responses can be undetectable in the first decade of life while photopic responses are reduced on the ERG at all ages.  Both rod and cone responses may be extinguished in later life.  Visual acuity can be decreased beginning in early childhood and legal blindness usually occurs by the second or third decade of life.  However, the loss of vision continues to progress and severe vision loss to finger-counting may be present in older individuals.  A scallop-bordered lacunar atrophy may be seen in the midperiphery.  The macula is only mildly involved by clinical examination although central retinal thinning is seen in all cases.  Dyschromatopsia is mild early and usually becomes more severe.  The visual fields are moderately to severely constricted although in younger individuals a typical ring scotoma is present.  The peripheral retina contains ‘white dots’ and often resembles the retinal changes seen in retinitis punctate albescens.

Systemic Features: 

None reported.

Genetics

Homozygous mutations in the RLBP1 gene (15q26.1) are responsible for this disorder.  Homozygous mutations in RLBP1 have also been found among patients with fundus albipunctatus (136880), retinitis punctata albescens, and in Bothnia type retinal dystrophy (607475),

NFRCD clinically resembles Bothnia type retinal dystrophy (607475) which likewise results from mutations in the RLBP1 gene but the maculae appear normal or have only a mild ‘beaten-bronze’ atrophy.

See Flecked Retina entry for somewhat similar conditions.

Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 

References

Hipp S, Zobor G, Glockle N, Mohr J, Kohl S, Zrenner E, Weisschuh N, Zobor D. Phenotype variations of retinal dystrophies caused by mutations in the RLBP1 gene. Acta Ophthalmol. 2014 Nov 27.  [Epub ahead of print].

PubMedID: 25429852

Eichers ER, Green JS, Stockton DW, Jackman CS, Whelan J, McNamara JA, Johnson GJ, Lupski JR, Katsanis N. Newfoundland rod-cone dystrophy, an early-onset retinal dystrophy, is caused by splice-junction mutations in RLBP1. Am J Hum Genet. 2002 Apr;70(4):955-64.

PubMedID: 11868161