Table 1.

Comparison of gene supplementation and CRISPR-Cas9 genome editing strategies.

Feature	Gene Supplementation	CRISPR-Cas9 genome editing
Can be used to treat autosomal recessive disorders	✓ Although currently restricted by gene size	✓ No restrictions of gene size but limited by gene editing loci
Can be used to treat dominant-negative conditions	✓	✓
Can be used to treat autosomal dominant diseases		✓
Can correct pathogenic variants		✓
Modifies disease without altering the genome	✓
Causes host immune response	✓	✓
Risk of genotoxicity from overexpression	✓
Potential off-target effects, such as cleavage or genetic modification of DNA regions other than the intended target site		✓