Her DNA became the key. Using the publicly available GEDmatch database, investigators discovered she was a distant relative of the killer. They built a sprawling family tree and followed it to Joseph James DeAngelo Jr., a former police officer living in Sacramento. A tissue he discarded confirmed the match, and in 2020, DeAngelo pleaded guilty to 13 murders and 13 kidnappings.

The case was the first high-profile crime solved using consumer genetic testing. Since then, millions have sent in their own samples—to companies such as 23andMe and AncestryDNA—to explore ancestry, uncover health risks or trace long-lost relatives.

As people turn to DNA to unlock the stories of their past and future, the science often reveals something messier—and far less certain—than they imagined. In the process, our understanding of family and identity can be upended.

When DNA reshapes identity

In fact, the revelations can be shattering: a parent who isn’t biological, or siblings who, suddenly, aren’t your own. Yet, DNA also shows just how closely we’re all connected. The most recent common ancestor of all humans alive today lived only a few thousand years ago—a point USC Dornsife geneticist Michael “Doc” Edge emphasizes in his genetics class.

“I’ve got bad news for all of you,” Edge, assistant professor of quantitative and computational biology, tells his students on the first day of class. “You’re related to me. We’re all related.”

But if we’re all connected, why can uncovering ancestry sometimes be so destabilizing? Why can it unravel cherished family stories or shake a person’s sense of self?

Police windfall, privacy minefield

Genetic data has proliferated at an unprecedented scale—and some of it is now searchable online. This development happened quickly, with almost no public debate.

Americans have long opposed the idea of a national DNA database, citing privacy concerns. But under the radar, consumer genetics has created something close to one. Only about 7% of Americans have taken a home DNA test, yet thanks to the mathematics of shared DNA, nearly everyone is now traceable.

“Only around 1% of the population needs to upload their DNA into a database searchable by law enforcement for virtually everyone to be findable,” says Edge. “So, a small group of participants has created a de facto national DNA database.”

For the police, it’s a windfall. But it’s also a privacy minefield. When one person shares their DNA, they’re effectively making decisions on behalf of their entire extended family. Edge’s research has shown how bad actors could manipulate these databases, potentially exposing users—and their relatives—to phishing attacks or other malicious actions.

Meanwhile, forensic genealogists—the specialists who build family trees to identify suspects—have been caught dodging database rules. In 2023, a whistleblower revealed that some investigators routinely searched data from people who had explicitly opted out of law enforcement use.

And life insurance companies could, in theory, sift through DNA data to assess medical risks.

There’s no evidence this has happened—yet. But there is no law to prevent it. “I think society still doesn’t understand the risk landscape,” says Edge. “And we’re definitely underprepared.”

“We’re learning that genes don’t matter as much as people thought,” says Patrick Turley, associate professor (research) of economics, who studies how genes influence health, behavior and social outcomes.

“We used to believe there might be individual genes that have major effects on diabetes, or even IQ. What we know now is very different: Traits are shaped by all our genes working in concert. Millions of genetic markers nudge us in subtle ways, shaping probabilities rather than certainties,” says Turley, who directs the Behavioral and Health Genomics Center at USC Dornsife.

Consider our health. Some conditions, such as Huntington’s disease, stem from a single faulty gene. But most hereditary illnesses involve vast networks of genes, each exerting only the faintest influence. In this chaotic landscape, predicting an individual’s risk becomes extraordinarily difficult.

Still, knowing you carry a higher risk than average can be helpful. Doctors already ask about family history; genetic testing can complement that by flagging patients who might benefit from earlier screenings or more frequent monitoring.

But having a genetic risk factor is not a prediction. DNA, Turley says firmly, is not “some mythical force.” Tell someone their diabetes risk is 25% instead of 20%, and that small bump can feel like destiny. “People tell themselves, ‘I’m a person who is at high-risk for diabetes,'” he says. But in fact, it’s a tiny difference that will have a negligible effect.

Even height—often cited as a success story of genetic prediction—reveals the limits of science. Researchers analyzed 5.5 million genomes tied to measured heights, yet their best model could explain less than half of the variation. “It’s a huge effort to obtain predictions that, in the end, are simply not that good,” says Turley.

The challenge goes deeper: Most genetic datasets come from people of European descent, making predictions less accurate when applied to other populations. The gap widens further for complex traits like intelligence or educational attainment. Using genetics to predict whether someone will graduate high school, Turley explains, “tends not to be useful for predicting a person’s individual outcome.”

Turley has also studied a new and often controversial frontier: embryo selection. Companies such as San Francisco-based Orchid Health now offer to test and rank embryos according to genetic risk factors.

The potential benefit, Turley says, is modest. In the best-case scenario, choosing the “best” embryo from 10 might, for instance, reduce the risk of diabetes from 35% to 30%. Yet companies rarely communicate such caveats to their clients, leading to confusion and overconfidence.

When DNA rewrites family

DNA’s influence—real or imagined—extends beyond health, touching identity, ancestry and the stories we tell about family.

Turley points to a familiar pattern: People raised to believe they had Native American ancestry discover they have no trace of it in their genome. For someone whose supposed Cherokee heritage shaped their identity—or who suddenly learns the father they love isn’t biological—the fallout can be profound.

Genetic testing companies know this. They recognize that what genetic genealogists diplomatically call “nonpaternity events” can be emotionally impactful, and some provide referrals to support services when results upend families.

In his genetics class, Edge offers a different frame for family—one meant to soften the authority we sometimes grant to DNA. “When I talk about somebody’s mom or dad or their cousin in this class, I’m using it as a shorthand for sources of gametes: sperm and eggs,” he says. “In reality, there are many other ways to define a family, and those other definitions are sometimes more meaningful.”

On the bonds that truly make a family—the shared experiences, the chosen commitments, the lives lived together—DNA is silent, Edge notes. And while genetic testing promises to reveal who we truly are, it also shows how little of our ancestors we carry.

“You don’t share any more DNA with your ancestors 10 generations back than you do with a random stranger,” he adds.

Even as genetic databases grow, the ties that bind remain the ones we weave ourselves, strand by strand, across a lifetime.

Women face multiple health issues, from infertility to breast, ovarian, cervical, and colorectal cancers. This is why early screening, awareness, and genetic insights become crucial to prevent and take timely care. Dr Syeda Zubeda, Medical Geneticist and Senior Genetic Counselor, Strand Life Sciences, tells Moneycontrol, “For too long, health check-ups and preventative screenings have been delayed until symptoms force action. But advances in genetics are offering women unprecedented insight into their bodies and risks.”

Infertility can be a deeply personal and frustrating challenge, affecting nearly half of couples at some stage. “Genetics can reveal the problem. Modern screening panels can examine multiple fertility-related genes at once, offering answers that may explain why conception is elusive.” says Dr Zubeda.

Safer prenatal testing

Pregnancycan be a time of excitement, and worry. “Traditional tests for chromosomal abnormalities sometimes required invasive procedures like amniocentesis, carrying small but real risks. Non-Invasive Prenatal Testing (NIPT), however, analyses tiny fragments of fetal DNA in the mother’s blood.” informs Dr Zubeda.

This allows early detection of conditions like Down syndrome without endangering the baby, while delivering more reliable results than older methods. It’s reassurance with science on your side.

Heart, metabolism, personalised wellness

According to Dr Zubeda, heart disease, diabetes, and metabolic disorders top the list of women’s health risks, and lifestyle advice alone doesn’t fit everyone. “Our genes shape how we process fat, sugar, and nutrients, meaning one diet or exercise plan rarely works for all. Nutrigenomics, the study of how genetics affect metabolism, helps women tailor nutrition, fitness, and lifestyle strategies to their unique biology.” she adds.

Understanding these personalised risk profiles turns guesswork into informed action.

Also read | Cancer, anaemia, poor nutrition, more: Biggest health challenges women face, how to prevent them

Early cancer detection

Cancer remains a leading cause of female mortality worldwide. Thanks to advances in genomic science, early warning signs can now be detected even before symptoms appear.

Dr Zubeda says, “Techniques like DNA methylation testing can flag abnormal changes in cells, enabling timely interventions for cancers such as breast, ovarian, and colorectal. Early detection saves lives, and gives women the advantage of choice and control.”

Hereditary cancer risk

Some cancers are inherited. They are linked to mutations in genes like BRCA1 and BRCA2. A simple blood test can reveal these hidden risks before cancer develops. This allows women to pursue early screening, preventive measures, or informed treatment planning.

FAQs on Women’s Health

1. What are some major health issues women commonly face?

Women often deal with infertility, heart disease, diabetes, metabolic disorders, and cancers such as breast, ovarian, cervical, and colorectal. Many of these can be better managed or prevented with early screening, awareness, and timely medical guidance.

2. How can genetics help with infertility in women?

Genetic screening panels can examine multiple fertility-related genes at once. This helps identify underlying causes of infertility, guiding doctors and couples toward targeted treatments, counselling, or assisted reproductive options, and reducing guesswork in the process.

3. What is Non-Invasive Prenatal Testing (NIPT)?

NIPT analyses tiny fragments of fetal DNA in the mother’s blood to screen for chromosomal conditions like Down syndrome. It offers early, more reliable results than some traditional tests, without the risks associated with invasive procedures like amniocentesis.

4. How do genes influence women’s heart and metabolic health?

Genes affect how women process fat, sugar, and nutrients. Nutrigenomics uses this information to personalise diet, fitness, and lifestyle strategies, making prevention and management of heart disease, diabetes, and metabolic disorders more precise and effective.

5. Can genetics help detect cancer risk in women early?

Yes. DNA methylation testing can detect abnormal cell changes before symptoms, aiding early detection of cancers like breast, ovarian, and colorectal. Blood tests for hereditary mutations such as BRCA1/BRCA2 also reveal inherited cancer risks, enabling proactive screening and prevention.

Disclaimer: This article, including health and fitness advice, only provides generic information. Don’t treat it as a substitute for qualified medical opinion. Always consult a specialist for specific health diagnosis.

Take the chilling cases of sudden cardiac deaths among elite athletes or seemingly healthy young adults diagnosed with advanced cancers—often without warning or obvious risk factors. According to Dr. Ashok Gopinath, Head – Partner Development, Strand Life Sciences, such scenarios, though rare, highlight a crucial truth: “It is quite well established that beyond advanced age and lifestyle, genes play a significant role in the onset of diseases like cancer and cardiovascular conditions.

In fact, about 10% of all cancers have a hereditary basis. “Inherited BRCA mutations, for instance, confer a 69–72% lifetime risk for breast cancer and a 17–44% risk for ovarian cancer,” adds Dr. Gopinath. That’s compared to baseline population risks of just 5–12% and less than 1%, respectively. Despite this, genetic testing has traditionally been recommended reactively—after symptoms, or a strong family history, surface.

But times are changing. Thanks to newer, non-invasive screening tools and plummeting costs, genetic testing is no longer a diagnostic tool of last resort—it’s emerging as a proactive strategy. Tests like Genomic Health Insights (GHI) by Strand Life Sciences now allow individuals to screen for over 280 adult-onset genetic disorders, including various cancers and heart diseases, even in the absence of symptoms. “We truly are fortunate to live in a time where every individual is empowered to take predictive tests and proactively understand their risk,” says Dr. Gopinath.

This is particularly powerful when it comes to reproductive health. “What if a quick test could say not only what your health is like today, but your likelihood of becoming a mother tomorrow?” asks Dr. Anshika Lekhi, gynaecologist and IVF specialist, The Fertilife, Gurgaon and a member of Doctube.

As someone who treats hundreds of women facing fertility struggles, Dr. Lekhi sees genetic testing as a revolution. “From uncovering hidden causes of infertility and miscarriage to detecting risks for PCOS, endometriosis, or premature ovarian failure, your DNA contains vital clues,” she explains. And it doesn’t stop there. For patients undergoing IVF, preimplantation genetic testing (PGT) helps select the healthiest embryos, thereby increasing the chances of a successful pregnancy. Non-invasive prenatal testing (NIPT), on the other hand, offers peace of mind by detecting chromosomal abnormalities early in pregnancy.

Most importantly, genetic insights can help women take control of their reproductive futures. “Whether it’s freezing eggs at 20 or addressing inherited conditions before they compromise fertility, the possibilities are staggering,” says Dr. Lekhi. “Your genes aren’t your fate—they’re your map. And genetic screening? That’s the compass guiding you intelligently.”

As science gives us more tools to understand our biology, the message is clear: we no longer have to wait for a diagnosis to act. In the evolving landscape of personalised healthcare, knowing your genetic risk may be the most empowering move you can make—for today and for the years to come.

Genetic testing can give important information for screening, diagnosing and treating health conditions, but it has limits. For example:

• A positive result doesn’t always mean that you’ll get the condition.
• A negative result doesn’t always mean that you won’t get the condition.

Talk with your healthcare professional, a medical geneticist or a genetic counselor before and after genetic testing to understand what the results mean for you.

Whole genome sequencing

When genetic testing is negative, or the results aren’t clear but a genetic cause is still suspected, some facilities offer more testing, such as whole genome sequencing.

Everyone has a unique genome, made up of the DNA in all of a person’s genes. Whole genome sequencing is a process for analyzing a sample of DNA. A sample is taken from blood or other sources such as saliva, a cheek swab or cells from the skin.

This complex testing can help identify genetic differences that may affect your health.

Why it’s done

Genetic testing can look at the risk of getting certain health conditions. Testing also can be used for screening, diagnosis and sometimes planning for medical treatment. Different types of genetic testing include:

• Diagnostic testing. When symptoms could be related to a condition caused by gene changes, genetic testing can help diagnose the suspected condition. For example, genetic testing can confirm a diagnosis of cystic fibrosis or Huntington’s disease.
• Predictive testing. If you have a family history of a genetic condition, genetic testing before you have symptoms may show if you’re at risk of getting the condition. For example, predictive genetic testing may show your risk of certain types of colorectal cancer.
• Carrier testing. You might choose to have genetic testing before having children if there is a history of an inherited condition or if you want to know your risk of certain hereditary diseases. This testing can show if you carry certain gene changes and could pass on a condition to your children. For example, you may have carrier testing if your family has a history of cystic fibrosis or if you’re in an ethnic group that has a high risk of a specific genetic condition, such as sickle cell anemia. Carrier testing also can tell if you and your partner both have gene changes for the same health conditions. An expanded carrier screening test can find genes linked with a wide variety of genetic conditions.
• Prenatal screening tests and diagnostic tests. Screening tests during pregnancy can show what the chances are that a baby has gene changes. Some prenatal screening tests look at genetic markers in a pregnant person’s blood. The prenatal cell-free DNA screening test uses a blood sample from the pregnant person to look at the baby’s DNA to help estimate the risk of Down syndrome and trisomy 18 syndrome, for example.

  Prenatal diagnostic tests can tell if a baby has certain genetic conditions. Diagnostic tests such as amniocentesis or chorionic villus take a sample of amniotic fluid from around the baby or tissue from the placenta to detect a genetic condition.

• Newborn screening. In the United States, all states require that newborns be tested for some genetic and metabolic changes that cause specific health conditions. Newborn screening can find conditions early so that treatment can begin right away to prevent complications. For example, newborn screening can suggest the presence of sickle cell anemia and phenylketonuria, also called PKU.
• Preimplantation testing. Also called preimplantation genetic diagnosis, this test may be used when trying to conceive a child through in vitro fertilization, also known as IVF. The embryos are screened for some genetic changes or a known genetic condition in the family before they’re implanted in the uterus.
• Pharmacogenetic testing. Also called pharmacogenomic testing, this genetic testing may help decide on the best medicine and dose for you. This type of testing is not routine. Ask your healthcare professional for more information.

Consumer genetic testing

You can buy consumer genetic tests without a prescription and send in a sample of saliva from your home. These also are called direct-to-consumer (DTC) genetic tests. Typically, you spit into a tube and send the sample to a company for testing. You may get your results in a letter or by visiting a webpage that’s protected by a password. The tests can tell you about your family history. Some tests give health-related information, but it may not be accurate. Clinical genetic testing by healthcare professionals is more accurate.

It’s not always clear what DTC genetic tests say about your health. Many factors specific to you may not be part of the results. The tests don’t always give clear answers about your health and shouldn’t be used to make medical decisions.

Before you use a DTC genetic test, check:

• What kind of results you’ll get.
• How accurate the test is.
• What happens to your DNA sample.
• The company’s privacy policy.

Talk with your healthcare professional or a medical geneticist or genetic counselor about the best genetic tests for you. These professionals also can help you understand the results.