As a teenager, Keoni Gandall was already operating a cutting-edge research laboratory in his bedroom in Huntington Beach, Calif.

While his friends were buying video games, he acquired more than a dozen pieces of equipment — a transilluminator, a centrifuge, two thermocyclers — in pursuit of a hobby that once was the province of Ph.D.’s in institutional labs.

“I just wanted to clone DNA using my automated lab robot and feasibly make full genomes at home,” he said.

Gandall was far from alone. In the past few years, so-called biohackers have taken gene editing into their own hands. As the equipment becomes cheaper and the expertise in gene-editing techniques, mostly Crispr-Cas9, more widely shared, citizen-scientists are attempting to re-engineer DNA in surprising ways.

Until now, the work has amounted to little more than DIY misfires. A year ago, a biohacker injected himself with modified DNA that he hoped would make him more muscular. (It did not.) Earlier this year, at Body Hacking Con in Austin, Texas, a biotech executive injected himself with what he hoped would be a herpes treatment. (Verdict: No.) His company had already livestreamed a man injecting himself with a home-brewed treatment for HIV. (His viral load increased.)

Gandall, now 18 and a research fellow at Stanford, said he only wants to ensure open access to gene-editing technology, believing future biotech discoveries may come from the least expected minds. But he acknowledged that the do-it-yourself genetics revolution one day may go catastrophically wrong.

“Even I would tell you, the level of DNA synthesis regulation, it simply isn’t good enough,” Gandall said. “These regulations aren’t going to work when everything is decentralized — when everybody has a DNA synthesizer on their smartphone.”

The most pressing worry is that someone will create a bioweapon. A team at the University of Alberta has recreated from scratch an extinct relative of smallpox, horsepox, by stitching together fragments of mail-order DNA in just six months for about $100,000 — without a glance from law enforcement.

To some, it nullified a decadeslong debate over whether to destroy the world’s two remaining smallpox remnants — at the Centers for Disease Control and Prevention in Atlanta and at a center in Russia — since it proved that scientists can create the virus themselves.

The study’s publication in the journal PLOS One included an in-depth description of the methods used and — most alarming to Gregory D. Koblentz, the director of the biodefense graduate program at George Mason University — a series of new tips and tricks.

“We’ve known this could be possible,” he said. “We also knew North Korea could someday build a thermonuclear weapon, but we’re still horrified when they actually do it.”

Many experts agree that it would be difficult for amateur biologists to design a killer virus on their own. But as more hackers trade computer code for the genetic kind, their skills will become increasingly sophisticated. “To unleash something deadly, that could really happen any day now — today,” said George Church, a researcher at Harvard. “Anyone who does synthetic biology should be under surveillance.”

U.S. authorities have been hesitant to undertake actions that could squelch innovation. The cobbled-together regulatory system, with multiple oversight agencies, has left gaps that will only widen as the technologies advance.

Academic researchers undergo strict scrutiny when they seek federal funding for experiments that, in theory, could be used for good or ill. But more than half of the nation’s scientific research and development is funded by nongovernmental sources.

“There really isn’t a national governance per se for those who are not federally or government funded,” said William So, a biological countermeasures specialist at the FBI.

Instead, So said, the agency relies on biohackers themselves to sound the alarm. The FBI has befriended many white-hat biohacking labs, among them Genspace in New York City, where biohackers-in-training — musicians, engineers, retirees — gather for crash courses in genetic engineering.

Gandall’s mission at Stanford is to build a body of genetic material for public use. To his biohackers, it’s a noble endeavor.

To biosecurity experts, it’s tossing ammunition into trigger-happy hands. “There are really only two things that could wipe 30 million people off of the planet: a nuclear weapon, or a biological one,” said Lawrence O. Gostin, a World Health Organization adviser. “Somehow, the U.S. government fears and prepares for the former, but not remotely for the latter. It baffles me.”