Related Experiment Video
Updated: Sep 22, 2025

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease
Published on: April 4, 2018
Phenotypic variant of CLN3 mutation
Avinash Honasoge1, Bradley T Smith1
1The Retina Institute, St. Louis, MO, United States.
Purpose:
To report a case of bilateral chorioretinal scarring due to CLN3 heterozygous deletion in an asymptomatic patient.
Observations:
A 63 year-old patient with a history of well-controlled diabetes presented as a referral for diabetic retinopathy. He was asymptomatic with 20/20 visual acuity in both eyes. Exam revealed bilateral multifocal chorioretinal scarring left worse than right, sparing the fovea. He was unable to provide a family history due to adoption, and his remaining medical history and review of systems were noncontributory. Inflammatory and infectious workup was negative; however, genetic testing revealed heterozygous deletion of CLN3 exons 8 and 9. His disease has been nonprogressive at all follow-up appointments.
Conclusions And Importance:
Mutations of CLN3 can present with retina-specific findings including bull's-eye maculopathy and electroretinogram (ERG) deficits; to our knowledge this patient's presentation is unique among those with CLN3 mutations.
Related Concept Videos
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Pleiotropy
Notch Signaling Pathway
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not...
Mutations
Point and Frameshift Mutations
Genetic Lingo

