Skip to content
New summer mock series is live Attempt timed papers for SSC, banking, and engineering entrances with updated syllabi for this season. View exams

Practice question

Question

Which platform has lowest off-target mutation rate?

Options

Choose one · Correct answer highlighted

Explanation

Off-target mutations determine safety for therapeutic genome editing. CRISPR tolerates mismatches distal to PAM generating relatively higher off-target cleavage. ZFNs and TALENs show lower tolerance due to longer protein-DNA interface and requirement for dimerization, yet still recognize near cognate sites. Homing endonucleases or meganucleases like I-SceI recognize 18-24 base pair asymmetric sequences, often exceeding 20 base pairs of specificity, resulting in rarity of cognate site in complex genome and extremely low off-target rate. Their long recognition site accounts for highest specificity among editing nucleases.