April Hauge, a nurse practitioner in Weimar, California, spent $500 on a genetic test for her autistic son in 2009 that led to purchasing thousands of dollars in vitamins and supplements. Impressed with the results, she's now selling advice on the approach to others.

There's just one problem: the DNA tests and related treatments have scant backing from science and U.S. government officials. They're untested, unproven, and may constitute "health fraud," doctors, regulators and concerned parents said.

For alternative-medicine providers in general, the genetic tests are nothing but a "marketing tool" to sell unproven treatments, said James Laidler, a retired physician and adjunct professor at Portland State University whose 19-year-old autistic son has tried alternative therapies.

"You always hear the testimonials from the people who got better, not the people who stayed the same or got worse," Laidler said. "They don't want to hear somebody saying this is snake oil."

Doctors and clinics across the United States are using the exploding science of DNA testing to feed anxieties and sell hope to people with autism and other hard-to-treat disorders.

Emboldened by meager state and federal regulation, purveyors of alternative medicine offer genetic tests costing hundreds of dollars to worried parents and patients, and then sell advice on supplements and diet based on results purporting to spot disease-causing deficiencies. They claim to be the panacea for everything from autism to chronic fatigue syndrome to the effects of aging.

"A lot of this skims on the edge of health fraud," said Janet Woodcock, director of the Center for Drug Evaluation and Research at the Food and Drug Administration, referring to the use of DNA testing to recommend alternative therapies.

Patients and practitioners say the tests and treatments are beneficial. The medical establishment has yet to catch on to the importance of common gene mutations, said Ben Lynch, a licensed naturopathic physician in Seattle and owner of a nearby supplement company.

Lynch's website focuses on a gene called MTHFR, and says that mutations in the gene are "a highly significant public health problem that is completely ignored."

"It takes a long time for standard medicine to learn about these things," he said. Those who dismiss the gene variants as unimportant "are totally wrong."

Lynch says his focus is on diet and lifestyle changes first, before supplements.

"I agree with some of these critics who say that if doctors are using genetic tests to sell lots of supplements, that is not ethical," Lynch said.

Mapping the genome is becoming a standard tool of medical care with new and cheaper DNA sequencing machines helping doctors unravel inherited diseases that once took years to diagnose. By searching for mutated genes in tumors, doctors can sometimes target them with special drugs that counteract the effect of rogue genes.

Researchers once hoped that common genetic variants would help predict the likelihood of major diseases like autism. Understanding the genetic component of autism has proven to be anything but simple. While scientists have documented thousands of statistical associations between genetic variants and diseases, definitive links haven't been confirmed in most cases.

After saying for about a decade that it has the power to regulate genetic testing, the FDA has yet to exercise its authority for most DNA diagnostics. While the U.S. Centers for Medicare & Medicaid Services regulates testing labs, it doesn't ensure that the tests are medically significant, or that doctors use them appropriately.

Alberto Gutierrez, director of the office of in vitro diagnostics and radiological health at the FDA, said the agency is "very concerned" about complex genetic tests being sold by laboratories, often over the Internet, whose claims are difficult to evaluate. Often, it may be difficult to even know who did the testing, he said.

"Nobody has looked at the evidence to support these tests," said Gutierrez, who wouldn't comment on specific genetic tests or test providers. "I am concerned that patients are being given unproven information that may result in less than optimal management of their disease."

Following public hearings in July 2010, the agency developed guidance for regulating complex genetic and other tests sold by laboratories. The rules have been under review by the Obama administration since late 2011, he said. Until they are finalized, the agency is "somewhat hamstrung" in cracking down on companies that sell the tests, Gutierrez said.

Testing laboratories facing potential new regulation "are concerned about the impact of what the FDA may do," he said.

In the meantime, patients and doctors "should proceed with caution" as some of the tests have not been well validated, Gutierrez said.

The vast majority of laboratory genetic tests provide valid medical information and are processed accurately and responsibly by licensed professionals, said Alan Mertz, president of the American Clinical Laboratory Association, a Washington-based industry group. Some doctors use valid tests to support "fringe" medicine, he said.

"The lab is just performing the genetic tests and reporting what the genetic makeup is of that DNA," he said in a telephone interview. "They don't know whether it's being used to prescribe supplements. They may have no idea what the doctor does with the information."

FDA approval procedures are too expensive and time- consuming for low-volume DNA tests processed by small labs, and would stifle the development of new tests that are now being developed by the hundreds, Mertz said. The group supports legislation by Texas Republican Representative Michael Burgess that would expand power at the Centers for Medicare & Medicaid Services to ensure that genetic tests give useful medical information.

One popular area in which genetic testing has taken hold is autism. Providers of alternative medicine treatments say the tests reveal toxicities and imbalances that may contribute to the mysterious, incurable brain disease.

Amy Yasko, a former biotechnology researcher with a Ph.D. in microbiology and immunology from Albany Medical College, has been touting "nutrigenomics" tests for autism for years. Most of the time she doesn't see patients in person or on the phone. Instead, she communicates with parents in online forums and puts out free Web lectures and books, including one called "Autism: Pathways to Recovery," full of complicated biochemistry lingo and diagrams of something called "the methylation cycle."

"Each child is completely unique — with a genetic profile unlike anyone else's," says her website, www.dramyyasko.com. "That's the reason you need a customized protocol just right for your child." The website says Yasko has had "considerable success in halting and in many cases reversing" diseases including autism, Alzheimer's disease, and amyotrophic lateral sclerosis.

The program usually starts with a genomic test "created by Dr. Amy Yasko, which can be ordered here," her website says. Clicking the link goes to another website of a company called Holistic Health International that sells a $495 nutrigenomics test, and supplements called "RNA Mutation Specific Formulas" for $85 each, as well as a variety of other treatments.

Parents of two autistic children who previously ordered Yasko's nutrigenomics test shared the results with Bloomberg. Both reports have Yasko's name on the front page and contain a chart of mutations in genes with names such as MTHFR, COMT, ACE, followed by a pages-long list of suggested supplements based on the genetic results.

In fact, there is little evidence suggesting that mutations in the genes can be used to design personalized autism treatment. A quick search of PubMed, a portal to scientific literature, instantly pulls up more than 4,800 scientific studies that mention the MTHFR gene, which has been studied in connection with a wide variety of disorders.

One 2012 study shows that a MTHFR mutation is just as common in migraine patients as people without the condition. Another research effort from the past year fails to show an association with schizophrenia.

Some of the strongest connections between MTHFR and disease were found in the 1990s, when preliminary research hinted that common mutations might boost heart disease risk, said Michael Tsai, a geneticist at the University of Minnesota.

Later studies cast doubt. In a 2012 study in Plos Medicine, researchers combined data from unpublished studies of over 116,000 patients and found no link between an MTHFR genetic variant and heart risk. Earlier studies to the contrary may have had "methodological problems," it concluded.

Tsai studied possible links between MTHFR genetic mutations and heart disease in the 1990s, but has since stopped working in the area because there is little evidence that it's important, he said.

"It doesn't seem that it is an important risk factor for anything," he said.

Yasko, in a telephone interview, says she cannot recall how many years ago she developed the nutrigenomics protocol and doesn't know how many people have used it. Her website says that 6,000 families are using "the Yasko Protocol" and that she has worked with families of autistic kids since 2003.

"I keep myself completely devoid of the business aspect of things," she said. "I am not involved with the sale of anything." She said she also isn't involved in the preparation of nutrigenomic test reports.

"What I do is I give information based on my reading and research that people can then go to their doctor with and utilize," Yasko said. "I don't promise anybody anything other than to say there are no magic bullets." She said she recommends safe, low doses of supplements.

In a brief telephone interview, Ed Yasko, Amy Yasko's husband, said he ran "the business end of things." He said the nutrigenomic test is performed by an outside lab that he wouldn't identify. Holistic Health International "is a retail outlet; we sell some supplements and we sell these tests," he said.

After reviewing the nutrigenomic test reports for the two autistic children, Daniel Coury, medical director for the Autism Speaks Autism Treatment Network, said there was no scientific evidence that the recommendations would combat autism.

Many genetic mutations examined in the test are also found in healthy people and there is no good evidence they cause autism, said Coury, who is also a developmental pediatrician at Nationwide Children's Hospital in Columbus, Ohio. The mutations, while they are real genetic variants, haven't been linked to nutritional deficiencies in autism patients, such as low levels of folate, which could easily be treated with vitamins, he said.

"It sounds scientific, but the connection to autism isn't there," he said. "I don't see any evidence that it is useful," he said.

A 2007 commercial lawsuit filed by Garry Gordon against the Yaskos said that the couple had formed a partnership to sell proprietary RNA supplements based on discussions starting in 2003, leading to the creation of a company called Nature's Formula that was led by her husband.

Amy Yasko and Gordon "were expressly not included" as owners of Nature's Formula or Longevity Plus, another company in the partnership, "in an effort to insulate them from potential liability" if users of the products brought successful claims, according to the lawsuit in federal district court in Arizona.

The parties sold "several million dollars worth of proprietary RNA supplements" during an almost three-year period, according to a separate 2007 lawsuit filed by Nature's Formula against Longevity Plus. Amy Yasko said she couldn't comment on the legal actions.

The whole concept of RNA supplements to treat specific genetic variants, such as ones sold by Holistic Health International, is "just laughable," said Laidler, the professor who has an autistic son. "Some of these families, they are so desperate."

Yasko "is exploiting the desperation of parents of autistic children," Laidler said. "She is selling them false hope."

April Hauge started reading medical textbooks about genetic diseases of metabolism after her son got sick. Hauge, who was then a nurse practitioner for Sutter Health, heard about Yasko through a patient who had used Yasko's test on her autistic son.

Skeptical at first, Hauge grew more interested after she went to a science lecture and, afterward, overheard several researchers vigorously debating whether Yasko's approach had merit. After trying Yasko's method on her own son, she soon started using a similar method to treat friends and family members suffering from various ailments.

She eventually was getting so many requests for help that she quit her nurse practitioner job and made it into a business.

"Five years ago, I would have laughed at anyone who told me about this," Hauge said. "This isn't accepted science."

Hauge now sells consultations for $190 an hour on nutrigenomics-based therapy for autism, Parkinson's disease, multiple sclerosis, and a host of other ailments. The consultations must be paid in advance, according to her website. In an interview, Hauge said she was booked through April 2013.

"I believe in this 100 percent," Hauge said. Patients with incurable ailments such as Parkinson's "don't have 20 years to wait" for formal studies. She said she doesn't sell supplements and barely breaks even on consulting because she does some work pro bono for people who can't afford to pay.

That kind of strong belief isn't enough to convince parents such as Kim Wombles to put her children on therapies that haven't been proven through rigorous scientific trials.

Some parents end up forcing 50 capsules down the throats of their young autistic kids daily, said Wombles, a blogger and mother of three autistic children in Abilene, Texas, who is highly skeptical of Yasko and others selling similar treatments.

"There is no way to know" about the safety of such complex supplement regimens, she said. "You are taking a crapshoot every time."

Parents may spend years trying to get the supplements to work, putting more and more money into more testing and supplement-dose tweaking, before they give up, Wombles said.