Wednesday, October 16, 2013

Learning a little more about RDH12 during Blindness Awareness Month

A little history about RDH12.  RDH stands for retinal dehydrogenase 12. - that is the official name of the gene.  A defect in this gene, which is what our kids have, is what causes them to have Lebers Congential Amaurosis. (LCA).  See, LCA is the BROAD umbrella for childhood blindness.  LCA is the most severe and most early onset of all the inherited retinal degenerations.  It is responsible for congenital blindness.  Every kid who has a gene affected through LCA is or will go blind.  This is a common factor.  There are 19 different types of LCA known right now, and RDH12 accounts for about 4% of those people affected with LCA.  So, about 85 people in the United States (because there are about 3000 people in the United States TOTAL that have one form of LCA).  Research in people with RDH12 affected genes have found these people to have severe, progressive rod-cone dystrophy. 

Here is an explanation of rod-done dystrophy:  There are two kinds of cells in the back of the eye called rods and cones.  They gather vision information from the light that comes into the eye through the pupil.  The cones are in the center of the back of the eye.  They gather information about details and color.  They work best in bright light.  (It may help you remember to think of “cones” and “color” both starting with “c.”) The rods are all around the rest of the back of the eye.  They gather information about things that move and things that are on the sides, above and below the person.  They work best in dim light.  People who have rod-cone dystrophy lose the use of the rods and cones. 

Still with me?  :)  Kids with RDH12 affected genes also have severe macular atrophy.  Macular dystrophy affects the retina in the back of the eye. Specifically, it leads to damage of cells in an area in the retina called the macula. The macula is responsible for central vision. When the macula is damaged, people have difficulty seeing straight ahead. This makes it difficult to read, drive, or perform other daily activities that require fine, central vision.  In macular dystrophy, a pigment builds up in cells of the macula. Over time, this substance can damage cells that are critical for clear central vision. Vision often becomes blurry or distorted. Typically, people with macular dystrophy maintain side (peripheral) vision, so they are not totally blind.

So - this is a start.  I won't overwhelm you with information.  But this gives a quick view of what is happening to our kids.  Severe vision loss.  And it is aggressive and unforgiving. 

1 comment:

Anonymous said...


That is interesting about LCA vision loss is also sad. I am so glad the RDH12 organization has you and your Husband as parents of a child with LCA. It is kind of like a blessing in discus? You can help the team learn more about LCA through your Daughter. :/ Forgive me. I am sorry I don't really know where I am going with this. Well, thank you for sharing. I wish you luck and prayers that there is a cure for Finley and the other kiddos too!! AMEN!