The cost of a personal genome has dropped from about the price of a luxury sedan to, well, the price of a slightly less luxurious nice car. Illumina, a genomics technology company headquartered in San Diego, announced the launch of a $48,000 genome-sequencing service at the Consumer Genetics Conference in Boston on Wednesday.

It won't be the first consumer genome service--Knome, a startup in Cambridge, MA, already offers genome sequencing for just under $100,000--but Illumina is the first company preparing to offer high-volume personal-genome sequencing. Knome, which uses Illumina technology to perform its sequencing, is a boutique service that offers both genome analysis and interpretation.

Many within the genomics industry believe that, as soon as the price is right, an individual's genome will be sequenced routinely and become part of her medical record. Within the genome lie clues to each person's risk for disease, his or her reaction to different medications, and other medically useful information.

While $48,000 is still out of reach for most consumers, the price reflects an exponential drop in the cost of sequencing technologies in recent years. James Watson's genome, sequenced in 2007, cost about $2 million, and Knome initially offered its service at $350,000. A third company, Complete Genomics, announced plans for a $5,000 sequencing service, although this will initially be available only to academic institutions and industry for research and clinical trials rather than for personal use. "It's like watching the price of gas fall," says George Church, a genomics technologist at Harvard University who has developed his own sequencing technology.

Unlike most consumer-genomics companies, which offer tests directly through the Internet, Illumina's genome-sequencing service will require a physician's prescription. In fact, the company will implement a seven-day waiting period after an individual surrenders his saliva for analysis to give customers time to make sure that they truly want to know the contents of their genome.

The $48,000 price tag comes with 30-fold coverage of the entire genome (an individual's DNA must be analyzed multiple times to generate a comprehensive sequence) but minimal analysis of the information that it holds. Instead, Illumina will leave the analysis to others, announcing partnerships with four major consumer-genomics companies: Knome, 23andMe, Navigenics, and Decode. Jay Flatley, Illumina's chief executive officer, said at the Consumer Genetics Conference that each company will develop its own analysis packages at an additional cost, and consumers will be able to pick the one that they want.