Congenital cone-rod synaptic disorder (CRSD), also known as incomplete congenital stationary night blindness (iCSNB), is a non-progressive inherited retinal disease (IRD) characterized by night blindness, photophobia, and nystagmus, and distinctive electroretinographic features. Here, we report bi-allelic RIMS2 variants in seven CRSD-affected individuals from four unrelated families. Apart from CRSD, neurodevelopmental disease was observed in all affected individuals, and abnormal glucose homeostasis was observed in the eldest affected individual. RIMS2 regulates synaptic membrane exocytosis. Data mining of human adult bulk and single-cell retinal transcriptional datasets revealed predominant expression in rod photoreceptors, and immunostaining demonstrated RIMS2 localization in the human retinal outer plexiform layer, Purkinje cells, and pancreatic islets. Additionally, nonsense variants were shown to result in truncated RIMS2 and decreased insulin secretion in mammalian cells. The identification of a syndromic stationary congenital IRD has a major impact on the differential diagnosis of syndromic congenital IRD, which has previously been exclusively linked with degenerative IRD.
In the originally published version of this article, the accession number given for RIMS2a was incorrect. It should have been NM_001348484.1. The number has now been corrected online. The authors regret the error.
Variants of the TTLL5 gene, which encodes tubulin tyrosine ligase-like family member five, are a rare cause of cone dystrophy (COD) or cone-rod dystrophy (CORD). To date, only a few TTLL5 patients have been clinically and genetically described. In this study, we report five patients harbouring biallelic variants of TTLL5. Four adult patients presented either COD or CORD with onset in the late teenage years. The youngest patient had a phenotype of early onset severe retinal dystrophy (EOSRD). Genetic analysis was performed by targeted next generation sequencing of gene panels and assessment of copy number variants (CNV). We identified eight variants, of which six were novel, including two large multiexon deletions in patients with COD or CORD, while the EOSRD patient harboured the novel homozygous p.(Trp640*) variant and three distinct USH2A variants, which might explain the observed rod involvement. Our study highlights the role of TTLL5 in COD/CORD and the importance of large deletions. These findings suggest that COD or CORD patients lacking variants in known genes may harbour CNVs to be discovered in TTLL5, previously undetected by classical sequencing methods. In addition, variable phenotypes in TTLL5-associated patients might be due to the presence of additional gene defects.
Background
Pathologic myopia is a major cause of visual impairment and blindness.
Case presentation
We report a case of an immediate post partum macular subretinal bleeding observed in a highly myopic patient. A 30-years-old woman presented two days after childbirth for sudden loss of vision in her right eye. Multimodal imaging showed macular hemorrhage masking a subtle yellowish linear lesion corresponding to lacker crack. Due to the lack of evidence for choroidal neovascularization, a simple clinical and imaging monitoring was recommended. Six weeks later, we noted an improvement in her best-corrected visual acuity and a decreased in size of the macular hemorrhage.
Conclusions
This is the first case reporting a macular subretinal bleeding on macular lacquer cracks in a highly myopic patient in immediate post partum.
Valsalva maneuver associated with vaginal delivery could explain the occurrence of the hemorrhage associated with lacquer crack. However, natural history of pathological myopia could not be excluded.
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