X-linked myopia 26 (Myopia 26, MIM #301010), which is caused by the variants of ARR3 (MIM *301770), is characterized by female-limited early-onset high myopia (eo-HM). Clinical characteristics include a tigroid appearance in the fundus and a temporal crescent of the optic nerve head. At present, the limited literature on eo-HM caused by ARR3 mutations shows that its inheritance mode is complex, which brings certain difficulties to pre-pregnancy genetic counseling, pre-implantation genetic diagnosis, and prenatal diagnosis. Here, we investigated the genetic underpinning of a Chinese family with eo-HM. Whole exome sequencing of the proband revealed a novel frameshift mutation in ARR3 (NM_004312, exon10, c.666delC, p. Asn222LysfsTer22). Although the mode of inheritance of the eo-HM family fits the X-linked pattern of ARR3, the phenotypes of three patients deviate from the typical early-onset high myopia. Through X-chromosome inactivation experiments, the patient’s different phenotypes can be precisely explained. In addition, this study not only enhanced the correlation between ARR3 and early-onset high myopia but also provided explanations for different phenotypes, which may inspire follow-up studies. Our results enrich the knowledge of the variant spectrum in ARR3 and provide critical information for preimplantation and prenatal genetic testing, diagnosis, and counseling.

Recently developed Prime Editor 3 (PE3) has been implemented to induce genome editing in various cell types but has not been proven in human hematopoietic stem and progenitor cells. Using PE3, we successfully installed the beta-thalassemia (beta-thal) mutations in the HBB gene in the erythroid progenitor cell line HUDEP-2. We inserted the mCherry reporter gene cassette into editing plasmids, each including the prime editing guide RNA (pegRNA) and nick sgRNA. The plasmids were electroporated into HUDEP-2 cells, and the PE3 modified cells were identified by mCherry expression and collected using fluorescence-activated cell sorting (FACS). Sanger sequencing of the positive cells confirmed that PE3 induced precise beta-thal mutations with editing ratios from 4.55 to 100%. Furthermore, an off-target analysis showed no unintentional edits occurred in the cells. The editing ratios and parameters of pegRNA and nick sgRNA were also analyzed and summarized and will contribute to enhanced PE3 design in future studies. The characterization of the HUDEP-2 beta-thal cells showed typical thalassemia phenotypes, involving ineffective erythropoiesis, abnormal erythroid differentiation, high apoptosis rate, defective alpha-globin colocalization, cell viability deterioration, and ROS resisting deficiency. These HUDEP-2 beta-thal cells could provide ideal models for future beta-thal gene therapy studies.

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss worldwide, with dry AMD representing the predominant form of the disease, although effective treatments remain limited. The pathogenesis of dry AMD involves dysregulation of the complement system and impaired antioxidant defenses, contributing to retinal pigment epithelium (RPE) and photoreceptor degeneration. Given the multifactorial nature of the disease, targeting a single pathological pathway may not adequately address its complexity. Here, we developed a single recombinant adeno-associated virus serotype 8 (rAAV8) vector designed to overexpress nuclear factor erythroid 2-related factor 2 (NRF2) while knocking down complement component 3 (C3). In an in vitro screen using ARPE-19 cells, NRF2 overexpression provided the strongest protection against sodium iodate (NaIO₃)-induced oxidative injury among the antioxidant candidates tested. We subsequently evaluated the dual-target vector in a mouse model of NaIO₃-induced retinal degeneration. Compared with NaIO₃-injured controls, the combination group showed significant improvements in electroretinographic responses and better preservation of retinal architecture. NRF2-containing treatment groups showed more favorable outcomes than shC3 monotherapy. Direct comparisons with NRF2 monotherapy revealed significant additional benefits of the combination for selected endpoints. These findings provide proof-of-concept evidence that dual targeting of oxidative stress and complement activation protects against NaIO₃-induced retinal degeneration, supporting further evaluation of this approach in complementary chronic models.