Fundus albipunctatus (FA) is a rare, congenital form of
night blindness with rod system impairment, characterised by the presence of numerous small, white-yellow
retinal lesions. FA belongs to a heterogenous group of so-called flecked retina syndromes. This disorder shows autosomal recessive inheritance and is caused mostly by mutations in the RDH5 gene. This gene encodes the
enzyme that is a part of the visual cycle, the
11-cis retinol dehydrogenase. This study is a brief review of the literature on FA and a report of the first molecular evidence for RDH5 gene mutation in a Polish patient with this rare disorder. We present a novel pathogenic RDH5 gene mutation in a 16-year-old female patient with symptoms of
night blindness. The patient underwent ophthalmological examinations, including colour vision testing, fundus photography, automated visual field testing, full-field electroretinography (ERG) and spectral optical coherent tomography (SOCT). The patient showed typical FA ERG records, the visual field was constricted and fundus examination revealed numerous characteristic, small, white-yellowish
retinal lesions.
DNA sequencing of the RDH5 gene coding sequence (exons 2-5) enabled the detection of the homozygous missense substitution c.524A > T (p.Tyr175Phe) in exon 3. This is the first report of RDH5 gene mutation that affects the invariant
tyrosine, one of the most conserved
amino acid residues in
short-chain alcohol dehydrogenases/
reductases (SDRs), crucial for these
enzymes' activity. The location of this substitution, together with its predicted influence on the
protein function, indicate that the p.Tyr175Phe mutation is the cause of FA in our patient.