Scientists successfully use CRISPR to fix a genetic mutation causing Hypertrophic Cardiomyopathy disease
Scientists for the first time have successfully repaired a genetic mutation in human embryos by using a gene-editing tool called CRISPR-Cas9.
It has freed embryos of faulty DNA that causes deadly hereditary heart disease. It potentially opens the door to preventing 10,000 disorders that are passed down the generations.
Using CRISPR-Cas9 gene-editing technology, scientists were able to repair mutation in the MYBPC3 gene which causes a common heart condition called hypertrophic cardiomyopathy, which is marked by thickening of the heart muscle.
Hypertrophic cardiomyopathy is an inherited cardiac disease and the presence of even one copy of the defective gene can cause symptoms, which usually manifest as heart failure. There is currently no cure for the condition. The correction of the mutation in the embryo using CRISPR-Cas9 has ensured that the child is born healthy and the defective MYBPC3 gene is not passed on to future generations.
How it was achieved?
The CRISPR-Cas9 gene-editing tool was used to remove the genetic mutation and introduce healthy gene in sperm of man with hypertrophic cardiomyopathy. This sperm was later fertilised with eggs from 12 healthy women. It was found that 42 out of the 58 fertilised embryos did not carry the mutation. The remaining 16 embryos had unwanted additions or deletions of DNA. It showed that probability of inheriting the healthy gene increased from 50 to 72.4%.
CRISPR-Cas9 gene-editing technology
Using CRISPR system, scientists can remove, add or alter specific DNA sequences in the genome of higher organisms. It has two components, a single-guide RNA (sgRNA) that contains a sequence that can bind to DNA, and Cas9 enzyme which acts as a molecular scissor that can cut specific DNA sequence. In order to selectively edit a desired sequence in DNA, the sgRNA is designed to find and bind to the target.