Cutting-edge technologies to repair the underlying mutations that cause Rett
There are several different types of gene editing technologies. Our programs use the highly efficient CRISPR-Cas system, which consists of two key molecules. The first is an enzyme called Cas9, which acts as a pair of molecular scissors that can cut DNA at specific locations so that bits of DNA can then be added or removed. The second is a guide RNA that brings the Cas9 enzyme to the proper location in the genome.
A Deeper Dive
into the Science
Genes are made up of specific nucleotide bases (A, T, C and G), which encode for amino acids. Every three bases code for a specific amino acid. The MECP2 gene has 1,497 nucleotide bases (A,T,C,G) that code for the 498 amino acids in the MECP2 protein. Alterations in the MECP2 gene range from a single letter to large sections of the gene being deleted or inserted. (To learn more about the genetics of Rett syndrome please visit our Genetics Primer.)
Beam Therapeutics is focused on editing point mutations — mutations caused by a single nucleotide base error. This approach, known as “base editing,” would require a novel therapeutic to be developed for each point mutation. Another group, led by Jonathan Watts at University of Massachusetts Medical School, is pursuing “exonic editing,” in which a single therapeutic would replace all of the 1,435 nucleotides in exons 3 and 4 and thereby correct 97% of all known mutations that cause Rett syndrome.