TIME Explains: Genome Sequencing

By Bonnie RochmanOct. 22, 2012

Read more: http://healthland.time.com/2012/10/22/time-explains-genome-sequencing/#ixzz2Ago7aK3y

Nearly every cell in the human body—from the ones in the fingernails to the ones deep inside the brain—contains a complete set of DNA, the operating instructions that influence everything from a person’s hair color to susceptibility to disease.
For years, doctors have been able to test specific genes to detect the presence of mutations associated with disorders such as cystic fibrosis and sickle cell disease. But only recently have scientists been able to map out a person’s entire genetic code, or genome, by sequencing all 20,000 or so genes in one fell swoop. (Read TIME’s five-part series on the promise — and pitfalls — of sequencing children’s genomes)