2026-06-25 | Programmed axon degeneration gene variants in human disease.

Programmed axon degeneration (PAD; also known as Wallerian degeneration) is a conserved pathway controlling axon breakdown following injury or metabolic stress. PAD is driven by the depletion of nicotinamide adenine dinucleotide (NAD) through loss of the pro-survival enzyme NMNAT2 and activation of the pro-degenerative NADase SARM1. Recent genetic studies have identified pathogenic variants in PAD pathway enzymes associated with severe neurodegenerative phenotypes. Pathogenic variants in NAMPT, NMNAT1, NMNAT2, and SARM1 have been identified and will be discussed in this review. NAMPT variants cause sensory and motor neuropathy with neurodevelopmental symptoms. NMNAT1 variants are well-characterized causes of Leber Congenital Amaurosis type 9, while NMNAT2 variants result in peripheral neuropathies with childhood onset. SARM1 gain-of-function variants with constitutively active NADase activity are enriched in amyotrophic lateral sclerosis patients. These findings demonstrate that maintaining proper NAD homeostasis is crucial for axon survival, and disruption through genetic variants leads to distinct neurodegenerative outcomes. Understanding these rare variants provides insight into PAD mechanisms and supports development of broad-spectrum neuroprotective therapies targeting this pathway. Current therapeutic approaches include SARM1 inhibitors in clinical trials, gene therapy, and NAD precursor supplementation, offering hope for treating multiple neurodegenerative diseases.

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2026-06-25 | Ora visual navigation course™ mobility test results in two individuals with CEP290 LCA after intravitreal injection of antisense oligonucleotide.

This study aimed to report the longitudinal Ora Visual Navigation Course (Ora VNC™) mobility test results in two individuals, with CEP290 LCA following intravitreal injections of an antisense oligonucleotide, sepofarsen. Two individuals were enrolled in the Illuminate Phase 3 trial and subsequently in the Post-Trial Access (PTA) program, undergoing Ora VNC™ across 12 visits. Subject 1 was initially randomized to the control (sham) group and switched to treatment from control group from the month 12 visit onwards. This individual passed only a few courses but demonstrated signs of enhanced spatial perception (defined by, among others, the ability to perceive objects' shapes and sizes). FST (full-field stimulus threshold) supported the light sensitivity gain in this subject. In contrast, subject 2, who received treatment since baseline visit, successfully completed mobility tests in all visits with progressive improvement, reaching lower luminance and more challenging contrast settings over time. According to the technicians' report, both subjects demonstrated an increase in perceived obstacle recognition during iterations, which may reflect improvement of mobility-based visual function outcomes. The Ora VNC™ mobility test captured mobility-based visual function gains, including subtle spatial improvements, but may lack sensitivity in individuals with extremely low vision, potentially overlooking small but patient-relevant changes.

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2026-06-23 | Trends in the Engineering of Adeno-Associated Virus (AAV) for Precision Gene Delivery to the Central Nervous System (CNS)

Rare genetic disorders of the central nervous system (CNS) remain some of the most complex and challenging diseases to treat for several reasons. Targeting the CNS, especially the brain, presents one of the greatest obstacles in gene therapy using adeno-associated virus (AAV) vectors. Although various AAVs have been identified for their ability to transduce different cells in the CNS, their effectiveness and efficiency are significantly limited by the presence of neutralising antibodies (NAbs) and restricted cargo capacity. Despite these challenges, our understanding of AAV structure and technological advances continue to enable researchers to develop innovative strategies that have resulted in groundbreaking, FDA-approved therapeutic products now available for Leber congenital amaurosis (LCA) (Luxturna®), spinal muscular atrophy (SMA) (Zolgensma®), and the two recent gene therapy products for aromatic L-amino acid decarboxylase (AADC) deficiency, Kebilidi® and Upstaza®, which currently hold FDA and EMA approval, respectively. This review aims to highlight recent advances in the field of AAV gene therapy for neurological disorders, identify research gaps, and suggest areas for future investigation to enable potential breakthroughs particularly in neurodegenerative, neurodevelopmental, and neuromuscular disorders. We foresee that more tissue- and cell-specific AAV vectors designed using AI-powered platforms will emerge to precisely and efficiently target specific brain regions, transforming how CNS disorders are treated.

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2026-06-13 | Therapeutic applications of gene editing using CRISPR-Cas9 in the posterior segment: review of the literature.

CRISPR-Cas gene editing has become increasingly relevant in the treatment of several ophthalmic diseases. Its ability to make precise modifications at the DNA or RNA level has enabled targeted approaches for specific mutations involved in conditions such as Leber congenital amaurosis type 10 (LCA10), certain forms of retinitis pigmentosa, and age-related macular degeneration. This article provides an organized overview of the biological basis of CRISPR-Cas technology and highlights key advances from preclinical studies and early clinical trials. Technical limitations and ongoing safety challenges are also discussed. Programs such as EDIT-101, EDIT-103, and HG202 stand out as important milestones in the evolution of ocular gene editing.

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2026-05-25 | Halofantrine protects photoreceptors in multiple models of retinal degeneration.

Inherited retinal degenerative diseases (IRDs), including retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA), cause progressive vision impairment due to photoreceptor degeneration. We previously demonstrated the protective effects of reserpine in models of CEP290-LCA and in the female Rhodopsin-P23H rat model of autosomal dominant RP. Given that reserpine is limited by side effects, we expanded our compound screen using retinal organoids from the rd16 mouse model of CEP290-LCA to include structurally diverse small molecules that may converge on proteostasis pathways. Follow-up evaluations in Rhodopsin-P23H rats, human CEP290-LCA retinal organoids, and rd10 mice (a model of PDE6B-RP) identified halofantrine as the most promising molecule, conferring strong protection to both rod and cone photoreceptors and demonstrating therapeutic potential across the divergent IRD models tested. Transcriptome analysis revealed a convergent molecular response to halofantrine across these models, primarily through upregulation of oxidative phosphorylation and ribosomal processes. Notably, halofantrine elicited significant improvements in retinal function, as assessed by electroretinography, despite pharmacokinetically limited and transient retinal exposure after subconjunctival injection in Rhodopsin-P23H rats. Our studies highlight the potential of halofantrine as a gene-independent therapy and suggest that it may be developed for ocular delivery via eye drops for the treatment of IRDs.

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