1. Autosomal dominant gyrate atrophy-like choroidal dystrophy revisited: 45 years follow-up and association with a novel C1QTNF5 missense variant
- Author
-
Ulrich Kellner, Nicole Weisschuh, Ghazaleh Farmand, Pascale Mazzola, Friederike Kortüm, Silke Weinitz, Sebastian Deutsch, Karin Schäferhoff, Valerio Marino, and Daniele Dell'Orco
- Subjects
0301 basic medicine ,Retinal degeneration ,Male ,Models, Molecular ,late-onset retinal dystrophy (LORD) ,Pathology ,autosomal dominant gyrate atrophy-like choroidal dystrophy (adGALCD) ,long-term follow-up ,C1QTNF5 ,lcsh:Chemistry ,0302 clinical medicine ,Genotype ,Missense mutation ,Age of Onset ,lcsh:QH301-705.5 ,Spectroscopy ,Genes, Dominant ,General Medicine ,Middle Aged ,Phenotype ,Computer Science Applications ,Pedigree ,Choroidal neovascularization ,Disease Progression ,Female ,genetic modeling ,Collagen ,medicine.symptom ,Tomography, Optical Coherence ,Adult ,medicine.medical_specialty ,Adolescent ,Fundus Oculi ,Static Electricity ,Mutation, Missense ,Biology ,Catalysis ,Article ,Inorganic Chemistry ,03 medical and health sciences ,Protein Domains ,medicine ,Gyrate Atrophy ,Humans ,Physical and Theoretical Chemistry ,Molecular Biology ,Gene ,Choroid ,Point mutation ,Organic Chemistry ,Haplotype ,medicine.disease ,030104 developmental biology ,lcsh:Biology (General) ,lcsh:QD1-999 ,030221 ophthalmology & optometry ,Visual Fields ,Follow-Up Studies - Abstract
We present a long-term follow-up in autosomal dominant gyrate atrophy-like choroidal dystrophy (adGALCD) and propose a possible genotype/phenotype correlation. Ophthalmic examination of six patients from two families revealed confluent areas of choroidal atrophy resembling gyrate atrophy, starting in the second decade of life. Progression continued centrally, reaching the fovea at about 60 years of age. Subretinal deposits, retinal pigmentation or choroidal neovascularization as seen in late-onset retinal degeneration (LORD) were not observed. Whole genome sequencing revealed a novel missense variant in the C1QTNF5 gene (p.(Q180E)) which was found in heterozygous state in all affected subjects. Haplotype analysis showed that this variant found in both families is identical by descent. Three-dimensional modeling of the possible supramolecular assemblies of C1QTNF5 revealed that the p.(Q180E) variant led to the destabilization of protein tertiary and quaternary structures, affecting both the stability of the single protomer and the entire globular head, thus exerting detrimental effects on the formation of C1QTNF5 trimeric globular domains and their interaction. In conclusion, we propose that the p.(Q180E) variant causes a specific phenotype, adGALCD, that differs in multiple clinical aspects from LORD. Disruption of optimal cell-adhesion mechanisms is expected when analyzing the effects of the point mutation at the protein level.
- Published
- 2021