A few years ago, Angela Evans decided she wanted to test the DNA of her 10-year-old daughter and 7-year-old son. She was interested in knowing whether they had a mutation of the MTHFR gene, as she does. The mutation is linked to a number of disorders — women with the mutation may have a higher risk of having babies with defects like spina bifida — and Ms. Evans wanted to make life changes for her children based on the results.

When doctors told her they didn’t think there was a medical need to test her children, she decided to use 23andMe, the direct-to-customer genetic testing company.

To use 23andMe’s services, the user simply sends in a saliva sample. Within five weeks the company returns the results, without the mediation of a doctor or genetic counselor.

Along with finding out that both her children had a mutation of the MTHFR gene, she also received 23andMe’s analysis of her children’s genetic susceptibility to a number of adult-onset diseases, including Parkinson’s. Ms. Evans shared the results with her children, family members and friends.

Then she uploaded their DNA data to MyHeritage and GEDmatch hoping to learn more about the family’s genealogy. Sites like GEDmatch and others are “open-source databases” on which people freely share their DNA online, usually in the hopes of finding long-lost relatives.

Ms. Evans is not alone in testing her children’s DNA. While 23andMe does not track how many of its kits have been used to test children, there’s a growing interest in genotyping children. And though 23andMe says its service is intended for adults, with its ads featuring animated characters, it appears to be marketing to children too. Similarly, the home testing companies Orig3n and Map My Gene market test kits specifically for testing children.

The problem with these tests is twofold. First, parents are testing their children in ways that could have serious implications as they grow older — and they are not old enough to consent. Second, by sharing their children’s genetic information on public websites, parents are forever exposing their personal health data.

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Upon a finding that they are at high risk for a disease, children may face negative consequences in school, the workplace and the insurance market — not to mention experience fear and anxiety about their impending fate.

“Not every child has the maturity to understand what things mean, and that could be an unfair burden on a kid whose whole life is ahead of him,” Dr. Naomi Laventhal, a neonatologist at the University of Michigan, has said.

Put simply, when parents test their children’s DNA before they are old enough to truly consent, those children lose their right not to know certain information. This is significant because, as Justice John Paul Stevens articulated in his 1977 Whalen v. Roe decision, there are two key components of the right to privacy: “the individual interest in avoiding disclosure of personal matters,” and “the interest in independence in making certain kinds of important decisions.”

In keeping with this standard, children should have the autonomy to decide to learn more about their genetic sequence only when and if they are interested.

In addition to the right to know or not to know the information in the first place, the corresponding right to prevent disclosure is a key issue in the case of home testing kits.

“Sharenting” — the phenomenon of sharing photographs, embarrassing stories and other personal information about one’s children online — has become commonplace. But in countries like France and Austria, children can sue their own parents for putting their childhood on display without their permission.

While this may seem extreme for mere pictures or stories, there is nothing more intimate and personal than a person’s DNA. Yet parents innocently share this information online — on the DNA sites, but also through blogs or Facebook groups — and often when their children’s results turn up something unexpected, like a surprising paternity result.

Dr. Louanne Hudgins, a geneticist at Stanford, cautions parents to consider the long-term privacy of their child’s health information collected through home genetic kits. Their children’s DNA and other health data, she has warned, could be sold to other companies — marketing firms, data brokers, insurance companies — in the same way that social media sites and search engines collect and share data about their users.

Furthermore, the American Academy of Pediatrics and the American College of Medical Genetics and Genomics strongly discourage the use of home-kit genetic testing of children.

The sharing of DNA results on open-source genealogy databases to find long-lost relatives poses another privacy risk: When parents share their children’s DNA on these sites, they are effectively sharing it with the world, including with the government and law enforcement investigators.

For example, law enforcement officials can compare DNA from crime scenes with DNA pulled from open-source websites. Even if parents attempt to keep their accounts anonymous, it is often not difficult for investigators to identify them and their children if anyone — even a relative as distant as a third cousin — has made a personal profile public.

Genetic privacy is just one part of a larger conversation about children’s privacy. While we have laws to protect children from third parties sharing children’s personal information online, these laws don’t apply when a parent does the sharing, or consents to allowing someone else to do it. This is because we have a legal tradition of allowing parents to determine what is in the best interests of their children.

But we find ourselves in a new era in which technology is outpacing most parents’ digital literacy. When parents upload their children’s test results to third-party sites, they likely do not consider the many possible consequences — some of which are listed only in the fine print of privacy policies most people never read.

Changing our laws to police parents or increase lawsuits, as in France and Austria, is most likely not the answer. Most parents share information online because they are proud of their children, not because they don’t care about their privacy. Rather than punishing parents with court battles, we should mount an educational campaign that would make disclosing children’s DNA information less socially acceptable.

The job of parents is to protect and nurture their children to the best of their ability. This should mean protecting the privacy of their DNA as well.

This article is part of The Privacy Project, an ongoing examination of privacy by The New York Times.

Nila Bala, a former teacher and juvenile justice attorney, is the associate director of criminal justice policy and civil liberties at the R Street Institute.