Czech and Slovak Ophthalmology 499 Original article The Molecular Genetic Cause and Clinical Findings in two Probands with Stargardt Disease Kousal Bohdan Záhlava Jiří 20 11 2014 6 4

Purpose: The aim of our study was to describe the phenotype and to perform molecular genetic investigation in two probands of Czech origin diagnosed with Stargardt disease (STGD). Methods: Both males underwent ocular examination including assessment by high-resolution spectral domain optical coherence tomography (SD-OCT). DNA was isolated from venous blood. Mutation detection was performed using the ABCA4 genotyping microarray (Asper Ophthalmics, Estonia). Results: The best corrected visual acuity in proband 1 (aged 39 years) was 0.1 bilaterally, and 0.05 in proband 2 (aged 26 years). Fundus examination showed typical multiple yellow-white lesions and macular atrophy. Alterations of retinal pigment epithelium, retinal thinning and disruption of the photoreceptor inner segment ellipsoid band were detected with an SD-OCT. Two known diseasecausing mutations in ABCA4 were identified in proband 1; c.4234C>T, p.(Gln1412*) in exon 28; and c.5882G>A, p.(Gly1961Glu) in exon 42. Only one pathogenic change was detected in proband 2; c.1988G>A, p.(Trp663*) in exon 14. A second change, anticipated because of the recessive status of the disease, was not identified. Conclusion: The frequency and full spectrum of ABCA4 mutations in Czech patients with inherited retinal disorders is yet to be established. The inability to detect a second pathogenic change in ABCA4 coding sequences in proband 2 warrants further investigation.

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