Post date: 
Tuesday, 6 June 2017
Uveal melanoma

Scientists hope new findings into genetic mutation leading to childhood blindness will help understanding of how genes contribute to the development of the eye.  

Researchers at the University of Edinburgh have identified the genetic mutation in children with ocular coloboma. Also known simply as coloboma, the condition accounts for 10 per cent of blindness in children and so far, little is known about the genetic causes.

The research has been funded by charity Fight for Sight. George McNamara, Director of Research, Policy and Innovation at Fight for Sight, said: “Sight loss due to coloboma in children can be devastating. Very little is known about the cause, and this study has helped advance our knowledge about the development of the eye. As this work progresses, we have the opportunity to come closer to understanding the causes of childhood sight loss.”

Children with the condition have a visible gap at the base of the pupil. This means the iris is shaped like a keyhole instead of being round. 
The keyhole shape happens if the pupil hasn’t fully closed during development in the womb. If the gap extends further into the eye, affecting the retina and the optic nerve, coloboma can severely affect vision.
The research, which will continue into 2018, has tested the DNA of 12 children with coloboma comparing it to their non-affected parents. Mutations were found in 10 genes, three of which were linked to activity of one molecule called actin. Actin is responsible for cell shape and structure as well as some other key functions.
The findings were then compared with 380 adults with coloboma and the mutation of one specific gene appeared in a number of those affected. This mutation, specifically affecting the gene ACTG1, was then edited in mice and findings showed a severe effect on actin.
Further information
NB News (archive)