Breakthrough in gene therapy: will people be treated for color blindness soon?

Monkeys got rid of color blindnessNikolay Podorvanyuk, "Newspaper.
Ru»English scientist John Dalton did not know until the age of 26 that he had visual impairments and did not distinguish between red and green colors.

Upon learning about this, he, like a true scientist, described the symptoms of this disease, which as a result received his name and is now called color blindness. The appearance of this disease is caused by a violation of the production of one or more photosensitive pigments in the visual receptors of cones – nerve cells of the central region of the retina.

Color blindness affects millions of people around the world, according to statistics, this disease is observed in 2-8% of men and less than 0.5% of women. This is due to the fact that the transmission of color blindness is inherited from the X chromosome and is usually transmitted from the mother, the carrier of the gene, to the son. The inability to distinguish red from green creates a number of problems for colorblind people, in particular because of this they cannot correctly perceive the traffic light signal.

"People suffering from color blindness are very worried about this disadvantage," says Jay Nitz, professor of ophthalmology at the University of Washington. – When we find a way to safely treat color blindness in humans, I am sure that many people will want to use it. In addition, there is a possibility that such technology will eliminate other vision problems."

All this awaits humanity in the future; meanwhile, a group of scientists from the University of Washington and the University of Florida managed to genetically cure color blindness in two individuals of squirrel monkeys. The results of their work are published in the journal Nature.

The experience of correcting color blindness in squirrel monkeys was initiated 10 years ago when Jay Nitz and his wife Maureen Nitz began working with two individuals named Dalton and Sam, who suffered from color blindness. (Approximately as in the drawings on the left, a colorblind monkey and a healthy monkey see the world around them.)

First of all, it was necessary to teach the animals to report what colors they see. To do this, a procedure similar to that used to determine the difference in colors by young children was applied – based on pictures depicting clusters of dots that differ from each other in size, color and its saturation (the picture on the right). When the monkeys correctly indicated the colors, they were rewarded with grape juice.

In parallel, William Hauswirth and colleagues from the University of Florida began to develop a gene transfer technique to correct color blindness. The general idea was to introduce the right gene into cells using a safe adeno-linked virus. Damage or absence of this gene in colorblind people leads to the absence or underdevelopment of light–sensitive receptors - opsins in their retina.

In the case of monkeys, we were talking about the so-called long-wave opsin, sensitive to radiation in the red part of the spectrum. At the same time, in the development of methods for the treatment of color blindness in monkeys, a gene from human DNA was taken as a basis, which will further facilitate the task of finding a method for the treatment of color blindness in humans.

As a result, five weeks after treatment, monkeys suddenly began to distinguish between red and green colors, and, as scientists found out over a year and a half of observations, up to 16 shades of each color. "We immediately found out when the treatment gave a result. They woke up and saw new colors for themselves," Nitz said. "We've been watching Dalton and Sam for ten years, and they're already like children for us. They are friendly and very obedient monkeys. We think it makes sense to continue watching them to see if their vision will change in the future."

There is no doubt that work in this direction will continue, and their main goal is to find a method of treating color blindness in people.

Portal "Eternal youth" http://vechnayamolodost.ru17.09.2009