BharatNotes What is CRISPR Gene Editing?
CRISPR-Cas9 is a genome-editing tool adapted from a defence system bacteria use against invading viruses. A short guide RNA (gRNA) carrying a roughly 20-nucleotide sequence directs the Cas9 enzyme to a matching stretch of DNA, where Cas9 makes a double-strand cut. The cell's own repair machinery then disables, corrects or inserts a gene at that site. Because the target is changed simply by reprogramming the guide RNA, CRISPR is dramatically cheaper, faster and more precise than older tools such as zinc-finger nucleases and TALENs.
The technique was published by Emmanuelle Charpentier and Jennifer Doudna in 2012, earning them the 2020 Nobel Prize in Chemistry — the first time two women shared a science Nobel.
Key Features and Applications
- Programmable precision — one enzyme (Cas9) plus a custom RNA guide can target virtually any DNA sequence.
- Medicine — correcting inherited disorders such as sickle cell disease and beta-thalassaemia.
- Agriculture — developing disease-resistant, drought-tolerant and higher-yielding crops.
- Diagnostics — CRISPR-based tests (e.g. India's FELUDA paper-strip test) detect pathogens.
A core ethical distinction is between somatic editing (changes to a patient's body cells, not inherited) and germline editing (changes to embryos, sperm or eggs that pass to future generations and are globally restricted).
Current Status (as of June 2026)
| Milestone | Detail | Date |
|---|---|---|
| Nobel Prize in Chemistry | Charpentier & Doudna | 2020 |
| First CRISPR therapy approved (world) | Casgevy, by UK MHRA | 16 Nov 2023 |
| US FDA approval of Casgevy | Sickle cell disease | 8 Dec 2023 |
| India's first indigenous CRISPR therapy | BIRSA 101 (CSIR-IGIB) | 19 Nov 2025 |
Casgevy (exagamglogene autotemcel), from Vertex Pharmaceuticals and CRISPR Therapeutics, edits a patient's blood stem cells to boost fetal haemoglobin. India's BIRSA 101, launched by Union Minister Dr Jitendra Singh on 19 November 2025, uses a fully indigenous enFnCas9 platform engineered at CSIR-IGIB, with technology transferred to the Serum Institute of India. It aims to slash the cost of treatment from roughly USD 3 million globally to around ₹50 lakh, directly aiding India's tribal population, which bears a heavy sickle cell burden.
India Policy Linkage and the Ethics Debate
BIRSA 101 complements the National Sickle Cell Anaemia Elimination Mission, announced in Union Budget 2023-24 and launched in July 2023, which targets elimination of the disease by 2047 across 17 high-focus states.
The defining cautionary episode is the He Jiankui affair of November 2018, when a Chinese scientist announced the world's first gene-edited babies — a germline experiment universally condemned as unethical; he was jailed for three years in December 2019. It crystallised the global consensus against heritable human editing and frames the GS4/Essay question of how to govern a powerful but morally fraught technology.
