NMNAT1 early-onset retinal dystrophy (EORD) caused by a novel 5'UTR splice donor variant
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Updated: Oct 31, 2026

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease
Published on: April 4, 2018
Paula C Morales1, Cesar Estrada-Puente1, Rachel D'Cunha1
1Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, USA.
Background:
NMNAT1 variants are a recognized cause of Leber congenital amaurosis (LCA), but NMNAT1-associated early-onset retinal dystrophy (EORD) phenotype remains rarely reported. Standard inherited retinal dystrophy (IRD) gene panel testing is limited in its ability to detect pathogenic non-coding variants, which are systematically excluded from conventional testing.
Materials And Methods:
A 6-year-old female underwent comprehensive ophthalmic examination, followed by a 330 gene IRD panel, whole-genome sequencing (WGS) and parental segregation.
Results:
The patient presented with nystagmus, esotropia, and reduced visual acuity. Multimodal imaging revealed atypical bilateral maculopathy while full-field ERG responses were borderline. The IRD panel was negative and subsequent WGS identified compound heterozygous NMNAT1 variant, a novel 5'UTR splice donor variant (c.-57 + 1 G > C) and a missense variant (c.480 G > C, p. Leu160Phe) confirmed to be in trans by parental segregation analysis.
Conclusion:
We report a novel NMNAT1 5'UTR splice donor variant in a case of NMNAT1-associated EORD, expanding the genotypic and phenotypic spectrum of NMNAT1 disease. Comprehensive genomic analysis is essential for diagnosing atypical IRD presentations.
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