Patients with RPE atrophy areas ≥0.05 mm2 secondary to STGD1 or AMD were included. RPE atrophy was defined as clearly demarcated definitely decreased fundus autofluorescence (FAF) under short-wavelength excitation light (488 nm) in combination with hypertransmission in optical coherence tomography (OCT).31,32 Insufficient pupil dilation, additional retinal pathology, previous retinal treatment, or other ocular comorbidities substantially affecting visual function or image quality (e.g., significant media opacity, amblyopia or optic nerve disease) led to exclusion from the study. The diagnosis of AMD was based on soft drusen and other retinal alterations consistent with the disease,9 while the diagnosis of STGD1 was based on (1) a compatible phenotype (yellow-white flecks that correlated with hyperautofluorescent flecks on FAF imaging) and (2) the presence of at least one mutated ABCA4 allele as well as the absence of mutations in peripherin-2 (PRPH2). To avoid potential confounding, patients exhibiting “diffuse-trickling geographic atrophy” were not included, as choroidal insufficiency has been previously implicated in the pathogenesis.33–37 Genetic testing was conducted at the Institute of Human Genetics, University of Regensburg (n = 7), and at the Center for Human Genetics Bioscientia, Ingelheim (n = 6). Analysis of all coding exons of the ABCA4 and PRPH2 genes was done by either direct chain-terminating dideoxynucleotide Sanger sequencing, a custom-designed GeneChip CustomSeq Resequencing Array (RetChip; Affymetrix, Santa Clara, CA, USA), or next-generation sequencing (Regensburg, n = 5; Bioscientia, n = 6). Two patients (#1 and #3) were screened for known mutations/polymorphisms using the Asper Ophthalmics ABCR400 microarray followed by Sanger sequencing to confirm selected variants.38 Only STGD1 patients with a minimum age of onset (first reported subjective symptoms) of 45 years were included as defined previously.38,39 Healthy subjects without retinal pathology served as controls.
Case#: Patient #13
DiseaseAssertion: STGD1
FamilyInfo: n/a
CasePresentingHPOs:
CaseHPOFreeText: RPE atrophy (clearly demarcated definitely decreased fundus autofluorescence (FAF) under short-wavelength excitation light (488 nm) in combination with hypertransmission in optical coherence tomography (OCT)) areas ≥0.05 mm2 secondary to STGD1 or AMD. diagnosis of STGD1 was based on (1) a compatible phenotype (yellow-white flecks that correlated with hyperautofluorescent flecks on FAF imaging) and (2) the presence of at least one mutated ABCA4 allele as well as the absence of mutations in peripherin-2 (PRPH2). Minimum age of onset (first reported subjective symptoms) of 45 years.
CaseNotHPOs:
CaseNotHPOFreeText: Insufficient pupil dilation, additional retinal pathology, previous retinal treatment, or other ocular comorbidities substantially affecting visual function or image quality (e.g., significant media opacity, amblyopia or optic nerve disease) led to exclusion from the study. “diffuse-trickling geographic atrophy”
GenotypingMethod: Analysis of all coding exons of the ABCA4 and PRPH2 genes was done by either direct chain-terminating dideoxynucleotide Sanger sequencing, a custom-designed GeneChip CustomSeq Resequencing Array, or NGS
PreviouslyPublished: possible since the study was at the same university with the same first author as PMID: 33214501
Variant: c.3468C>G/p.(Tyr1156*) and c.5059A>T/p.(Ile1687Phe)
ClinVar: n/a
CAID: CA341290648
SupplementalData: supplement 1 has the genotype for probands