Researchers have discovered a novel technique — that acts like a “spell-checker” for correcting a misspelling in the DNA code — to repair the defective gene that causes spinal muscular atrophy (SMA). This hereditary neuromuscular disease is the number-one genetic killer of children under two years old. Babies born with Type 1 SMA, the most severe form of the disease, can’t walk, crawl, sit unsupported, lift their heads, or breathe normally. Fifty percent die before their second birthday.