A peculiar autosomal dominant macular dystrophy caused by an asparagine deletion at codon 169 in the peripherin/RDS gene.

OBJECTIVE

To describe the clinical and genetic findings in a family with a peculiar autosomal dominant macular dystrophy with peripheral deposits.

METHODS

All family members underwent an ophthalmic examination, and their genomic DNA was screened for mutations in the human retinal degeneration slow (peripherin/RDS) and rhodopsin genes. In selected cases, fluorescein angiography and electrophysiologic testing were performed.

RESULTS

The age at onset of the disease was between the third and fourth decades of life, starting with mild visual acuity loss and periods of metamorphopsia. Clinical signs included subretinal yellowish macular deposits evolving into geographic atrophy and retinal hypopigmentation and hyperpigmentation. Electroretinography demonstrated rod dysfunction, and electro-oculograms were mildly to severely disturbed. All affected members were found to carry a 3-base pair deletion affecting codon 169 of the peripherin/RDS gene. This mutation resulted in an asparagine (Asn) deletion in the peripherin/RDS protein and was not found in 155 control individuals.

CONCLUSION

A deletion of Asn169 in the peripherin/RDS protein causes a peculiar form of autosomal dominant macular dystrophy in a large family from the Netherlands.

CLINICAL RELEVANCE

Characterizing the phenotype and genotype in this family may, in the long term, result in a better understanding of the precise mechanism underlying this retinal degeneration.