Related Experiment Video
Updated: Aug 9, 2026

Assessment of Zebrafish Lens Nucleus Localization and Sutural Integrity
Published on: May 6, 2019
Autosomal dominant zonular cataract with sutural opacities is associated with a splice mutation in the
C Kannabiran1, P K Rogan, L Olmos
1National Eye Institute, NIH, Bethesda, MD 20892-1860, USA.
Purpose:
Congenital cataracts constitute a morphologically and genetically heterogeneous group of diseases that are a major cause of childhood blindness. Autosomal Dominant Zonular Cataracts with Sutural Opacities (CCZS) have been mapped to chromosome 17q11-q12 near the betaA3A1-crystallin gene (CRYBA1). The betaA3A1-crystallin gene was investigated as the causative gene for the cataracts.
Methods:
The betaA3/A1-crystallin gene was sequenced in affected and control individuals. Base changes were confirmed and assayed in additional family members and controls using NlaIII restriction digestion of PCR amplified DNA sequences. Base changes were assessed for their effects on splicing by information analysis.
Results:
The cataracts are associated with a sequence change in the 5' (donor) splice site of intron 3: GC(g->a)tgagt. The sequence change also creates a new NlaIII site. This base change cosegregates with the cataracts in this family, being present in every affected individual. Conversely, this base change was not seen in 140 chromosomes examined in 70 unaffected and unrelated individuals. Information theory mutational analysis shows that the base change lowers the information content of the splice site from 6.0 to -6.8 bits, so that splicing would not be expected to occur at the altered site.
Conclusions:
Taken together, these observations suggest that the observed mutation might be causally related to the cataracts in this family.
Related Concept Videos
Genetic Lingo
Alternative RNA Splicing
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
Catenins
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...
Glaucoma: Overview
Photoreceptors and Visual Pathways

