Leber Congenital Amaurosis

09.05.2024

Leber Congenital Amaurosis

Why in the news?   

           Researchers have used a CRISPR-Cas9 tool to restore vision in a group of adults and children with congenital blindness known as Leber congenital amaurosis (LCA).

About Leber Congenital Amaurosis:

• It is a rare genetic eye disorder affecting infants who are often blind at birth. Children born with LCA have light-gathering cells (rods and cones) of the retina that do not function properly.
• It affects about one in 40,000 people and causes severe vision loss at an early age. This blindness is caused by a gene mutation that prevents a protein from functioning properly. That protein CEP290  is critical for sight.

Recent development:

• Scientists used a human gene editing tool, CRISPR-Cas9, to restore vision of people who are affected by this disorder and the trial was called “BRILLIANCE”.
• Participants in the study received a single dose of a CRISPR gene therapy called EDIT-101.
• In the case of EDIT-101, the treatment cuts out the mutation in CEP290 and inserts a healthy strand of DNA back into the gene. This restores normal function of the protein CEP290, allowing the retina to detect light.

 About the CRISPR-Cas9:

• It is a unique technology that enables geneticists and medical researchers to edit parts of the genome by removing, adding or altering sections of the DNA sequence.
• It is currently the simplest, most versatile and precise method of genetic manipulation and is therefore causing a buzz in the science world.

Application of CRISPR-Cas9

• Animal models: By mutating or silencing genes, CRISPR-Cas9 can be used to create animal models that mimic human diseases and help researchers understand disease development.
• Genome editing in specific tissues: Using hydrodynamic injection and adeno-associated virus (AAV), researchers were able to modify the genomes of specific tissues such as liver and brain.
• It can be used to generate mutants for multiple target genes.
• It was first used commercially to make resistant to viral infections bacterial cultures used in cheese production.
•  CRISPR-Cas9 can also edit single-stranded RNA (ssRNA) sequences.
• These studies are frequently focused on increasing soldiers' tolerance to biological or chemical warfare. This technology has the potential to improve human performance.

                                                                Source: Indian Express

Consider the following statements:

Statement-I

Leber congenital amaurosis is a rare genetic eye disorder which affects infants.

Statement-II

 Leber congenital amaurosis prevents the proper functioning of the protein-CEP290.

Which one of the following is correct in respect of the above statements?

A.Both Statement-I and Statement-II are correct, and Statement-II is the correct explanation for Statement-I.

B.Both Statement-I and Statement-II are correct, and Statement-II is not the correct explanation for Statement-I.

C.Statement-I is correct, but Statement-II is incorrect.

D.Statement-I is incorrect, but Statement-II is correct.

Answer A