If you've ever wondered what the mail-away gene-testing service 23andMe was doing with all the personal and family bio-information collected from its five million customers, here's one answer: Sharing it with GlaxoSmithKline, the British drug giant with major U.S. research labs in Collegeville and sales offices in South Philly's Navy Yard, so Big Pharma can target and treat your genetic defects, boosting sales and profits.

Glaxo said Wednesday it has agreed to invest $300 million in 23andMe, the Mountain View, Calif., gene-testing company best known for its retail gene reports designed to suggest where your ancestors hail from. The company says more than four-fifths of 23andMe customers — or over 4 million people — agreed when they signed up with the service to let their data be used for research, and now Glaxo's going to use it.

Anticipating privacy concerns that people who sent samples to 23andMe will be identified as subject to genetic diseases, the companies stressed in their joint statement that they "have stringent security protections in place when it comes to collecting, storing, and transferring information about research participants," including data encryption. The information will be "aggregated and de-identified" for Glaxo; only 23andMe would know customers' identities or contact them, said Glaxo spokeswoman Mary Anne Rhyne.

The deal raised immediate questions from medical ethicists and scholars. For example, what are the limits on the use of DNA samples when customers consent, asked Jon Merz, a lawyer and professor of medical ethics and health policy at Penn. "Arguably, the companies should be transparent about the terms of the arrangement — who owns what, who gets what, and whether the subjects, as a population, get anything of value" from giving their information.

Merz added in an email, "Expensive new targeted 'personalized' treatments may be of benefit to those who can afford them."

Other concerns include the disclosure of sensitive information in contacts and solicitations, and who owns a customer's information after they die.

Glaxo said in a statement that it plans "an exclusive four-year collaboration that will focus on research and development of innovative new medicines and potential cures, using human genetics as the basis." Glaxo plans to put "23andMe's large-scale genetic resources" collected from its "consenting" customers, together with GSK's own science and marketing, to "discover novel drug targets" for "serious unmet medical needs."

"We are excited about this unique collaboration, as we know that drug targets with genetic validation have a significantly higher chance of ultimately demonstrating benefit for patients and becoming medicines," said Hal Barron, president of research and development and chief scientific officer at Glaxo. "Partnering with 23andMe, an organization whose vision and capabilities are transforming the understanding of how genes influence health, will help to shift our research and development organization to be 'driven by genetics,' and increase the impact GSK can have on patients."

"Many" 23andMe customers have asked for "cures or treatments" for genetic diseases, 23andMe CEO and cofounder Anne Wojcicki said in a statement. "By leveraging the genetic and phenotypic information provided by consenting 23andMe customers and combining it with GSK's incredible expertise and resources in drug discovery, we believe we can more quickly make treating and curing diseases a reality."

Glaxo and 23andMe say the drug company will use the genetic data to "improve target selection" for "precision" medicines; learn more about genetic "pathways and mechanisms" for disease; and "support identification of patient subgroups that are more likely to respond to targeted treatments."

The four-million-plus customers who agreed to let their data be used "could help enable the discovery of a significant number of novel associations from a diverse range of people, which would not otherwise be possible," Glaxo added. It will "allow more effective identification and recruitment of patients for clinical studies" by helping identify "patients with a particular disease" or with genes prone to specific conditions. That will help speed up clinical research, the company said.

The deal allows Glaxo to extend the relationship for a fifth year. For its part, 23andMe says it already has "a portfolio of early stage therapeutic research programs across a wide range of disease indications that will be assessed for inclusion."

To that program, Glaxo plans to add its LRRK2 inhibitor, which it hopes to develop to treat Parkinson's disease. "Together, GSK and 23andMe are expected to more effectively target and rapidly recruit patients with defined LRRK2 mutations" for the Parkinson's therapy development. The companies will initially split costs.