Fifty hours. That’s how long it now takes to decode and interpret a newborn baby’s genome — an undertaking that used to take weeks or even months. And those two days can mean the difference between life and death for a critically ill infant. The speedier genomic analysis is possible thanks to advances in sequencing technology as well as innovative software that links the 3,500 known genetic defects to their childhood diseases, allowing doctors to quickly decide on the right treatment that could save a baby’s life. About 30% of babies admitted to the neonatal intensive care unit each year have inherited a genetic disease, and sequencing their genomes may become a critical part of improving their care in coming years — the sooner the better.