According to a recent study, scientists claimed to have cured progeria in mice with the help of gene-editing technique.
It was in 2009, when I came to know about a disease known as Progeria, when I saw Amitabh Bachchan playing the role of a young child who was suffering from this very rare disease in his movie ‘Paa’. Progeria is an extremely rare and highly fatal genetic premature-ageing syndrome in children, giving them a lifespan of around 14 years on average, and doesn’t have a cure yet. This progressive genetic disorder that causes children to age rapidly affects about one in 18 million children and results in premature ageing and death in adolescence.
But recently, scientists in a study claimed to have cured progeria in mice with the help of CRISPR gene-editing. Researchers, as per their latest study, have successfully used a DNA-editing technique to extend the lifespan of mice with the help of genetic variation associated with progeria, the disease that rapidly accelerates ageing and shortens life expectancy.
The Harvard-led study, also involving Vanderbilt University and the US government’s National Institutes of Health, demonstrated a method that can correct single-letter genetic mistake that causes thousands of diseases.
In this recent approach of researchers to cure progeria, scientists used a technique called base editing, which was originally inspired by the gene-editing technology CRISPR, to edit out a single base or one of the four letters of the DNA. This method basically aims to nurse specific mutation in the genome that produces progerin, a toxic protein that induces rapid ageing and shortening of lifespan.
Progeria: Child ageing disease
Progeria, also known as Hutchinson-Gilford syndrome, is an extremely rare genetic condition that causes a child to age prematurely. Children with progeria appear healthy during birth, but as they grow and by the time, they reach the age of two, their ageing rapidly accelerates making them look much older than their original age. A child suffering from this fatal disease has a lifespan of around 14 years on average.
Progeria is caused by a single gene mutation, a single ‘letter’ change in the LMNA gene structure of the DNA. For understanding this, it’s important to understand the basic structure of DNA.
A molecule of DNA consists of two strands that form a double-helical structure. It is made up of four nucleotides, or nitrogenous organic molecules that serve as building blocks. The bases that form the basic structure for the DNA are: cytosine (C), guanine (G), thymine (T), and adenine (A). These bases are basically coupled in the DNA structure in the form of pairs.
Progeria is caused by a mutation in the LMNA gene that codes for the lamin A protein. This ultimately causes the production of a toxic protein, called progerin, which damages cells in the body. As of now, there is no cure for the disease and patients usually die from cardiovascular failure around the age of 14. But as per the findings of this new study, scientists have found the first potential base-altering treatment to extend the lifespan of progeria patients.
Base editing offers hope for curing progeria
Treating most genetic diseases requires precise correction of the mutation rather than disrupting the gene. For this study, researchers used a breakthrough DNA-editing technique known as base editing. Through this technique, scientists substitute a single DNA letter for another without damaging the actual structure of DNA, to study how changing this mutation might affect progeria-like symptoms in mice.
Researchers found that the root cause of progeria in nearly all affected children is a single specific mutation in the LMNA gene structure of the DNA and in order to find a cure for the disease that needs to be fixed. The CRISPR-Cas9 technique makes double-stranded cuts in DNA, but still, it should be remembered that CRISPR editing, cannot yet make precise DNA changes in many kinds of cells.
Base editors modify DNA bases by changing one base or one letter to another without completely affecting the DNA structure or making double-stranded breaks in the structure. Although the results of clinical trials of CRISPR genome editing so far have been promising, researchers say that it is still too soon to know whether the technique will be safe or effective.