Why this study matters

Familial exudative vitreoretinopathy (FEVR) is an inherited retinal disease in which the retina’s blood vessels do not fully develop, particularly at the far edge of the retina. This peripheral non-perfusion can remain stable in some people, while in others it can lead to abnormal new blood-vessel growth, retinal scarring, detachment, and vision loss. Importantly, FEVR can look very different between families, between individuals with variants in the same gene, and even between a person’s two eyes.

A 2026 retrospective study from three UK paediatric retina centres examined 51 people with FEVR to better understand these differences. The researchers explored which genes were involved, how genetic variants may affect proteins, how severe disease was, and which treatments were used. For patients and families, the work adds to evidence that genetic findings can provide useful context for understanding FEVR, although they do not tell the whole story on their own.

Six genes identified across the cohort

The study found genetic variants in six genes already linked with FEVR:

  • FZD4: 16 patients
  • LRP5: 13 patients
  • TSPAN12: 11 patients
  • KIF11: 6 patients
  • NDP: 4 patients
  • CTNNB1: 1 patient

FZD4 was the most frequently represented gene in this cohort, followed by LRP5 and TSPAN12. These findings illustrate the genetic diversity underlying FEVR: a similar retinal appearance can arise from changes in different genes.

The team compared the identified variants with genomic and protein databases, including ClinVar, gnomAD, and UniProt. They also used computer-based prediction tools, MutationTaster and PolyPhen2, to assess whether a variant was likely to disrupt protein function. This analysis identified 11 variants that had not previously been reported in FEVR. Seven of these were classified as likely pathogenic, meaning the available evidence suggested they were likely to contribute to disease.

Finding previously unreported variants is valuable because it expands the catalogue of genetic changes clinicians and laboratories can consider when evaluating families affected by FEVR. It also highlights why genetic testing and careful variant interpretation are important: not every DNA difference is disease-causing, and understanding its significance may require multiple sources of evidence.

NDP variants linked to severe, uneven disease

One of the clearest genotype–phenotype observations involved NDP. In this cohort, NDP variants were associated with the most severe disease and the greatest asymmetry between eyes. Asymmetry means that one eye may be substantially more affected than the other.

This is particularly relevant in FEVR, where an apparently unaffected or mildly affected eye may still have peripheral vascular abnormalities. The study supports the importance of assessing both eyes carefully and continuing follow-up even when vision or clinical appearance differs markedly from one eye to the other.

At the same time, the cohort demonstrates that disease severity is not determined by genetics alone. FEVR showed considerable variation in clinical presentation and visual outcomes. A gene result can help inform clinical understanding, but it must be considered alongside retinal examination, imaging where appropriate, disease stage, and changes over time.

Management reflected the range of FEVR severity

Treatment decisions in the cohort reflected the broad clinical spectrum of FEVR. Among the eyes included, 45 were managed with conservative monitoring, 39 received retinal laser photocoagulation, and 12 underwent surgical intervention.

Laser photocoagulation is used to treat areas of peripheral retina without an adequate blood supply, with the aim of reducing the risk posed by abnormal vessel growth. Surgery may be considered in more advanced disease. Monitoring remains an important approach when active treatment is not indicated, since FEVR can vary in severity and requires individualized management.

Across all three management groups, most patients had stable or improved visual acuity. This is an encouraging finding, though it should be interpreted in the context of a retrospective study based on routine clinical records. The study describes outcomes in this group of patients rather than directly comparing treatments or establishing that one approach is superior to another.

Building a more genetically informed future

This research strengthens the case for combining genetic investigation with detailed clinical care in FEVR. Identifying the responsible gene may help explain patterns of disease, support assessment of relatives, and contribute to a growing evidence base linking particular variants with clinical features. The association between NDP variants and more severe, asymmetric disease is an example of how these connections may eventually help refine risk assessment and follow-up strategies.

The discovery of additional likely pathogenic variants also shows that the genetic landscape of FEVR is still being mapped. Larger studies, consistent staging, and longer-term follow-up will be needed to clarify how specific variants relate to disease progression, treatment choices, and visual outcomes. As knowledge grows, genotype–phenotype research may help guide the development of more targeted strategies for protecting vision in people with FEVR.