The products of thousands of interacting genes (Image: JGI/Jamie Grill/Blend Images/Getty)

A US genetics company has patented a DNA-analysis tool that allows people to pick sperm and egg donors based on what kind of offspring they want. But this week, after enquiries by New Scientist, it posted a denial that it plans to use the technology for anything more than as an engaging way to allow customers to see what kind of traits their child might inherit.

The denial could reflect its customers’ angry reactions last year when the company, 23andMe of Mountain View, California, which bills itself as democratising the genome, had its first patent granted. But it could also reflect accusations that such genetic shopping comes perilously close to eugenics – or may not work as advertised.

Neanderthal heritage

23andMe sequences DNA from a saliva sample for customers who pay $99. It says it is “dedicated to helping individuals understand their own genetic information” in the 23 human chromosomes. The company currently tells its 400,000 customers if they have various elevated disease risks, where their ancestors came from, and how Neanderthal they are.


In return, customers respond to surveys, allowing the company to do research associating DNA sequences with various characteristics, such as disease risk. Its first patent last year covered diagnostic and therapeutic applications of a gene it found was associated with Parkinson’s disease.

There was a negative outburst from people worried that the company would monopolise testing for the gene.

“There’s a tension between their claims to be open and transparent and the corporate need to find new revenue generation,” says Stuart Hogarth of King’s College London.

Flushed drinkers

The new US patent, issued on 24 September, covers the DNA-analysis method at work in 23andMe’s inheritance calculator, an interactive feature on the company’s website. This allows two customers to calculate the probability that their child will have certain phenotypes, or expressed genetic characteristics, produced by the various possible combinations of their genes.

It covers only six characteristics: eye colour; hard or sticky earwax; whether muscle fibres will be geared towards sprinting or endurance events; bitter taste perception; lactose tolerance; and whether offspring will flush when they drink alcohol. “It’s all just part of the fun of having a baby,” says 23andMe spokesman Donald Cutler.

The US patent, however, describes using the procedure as a “gamete donor selector” that allows a recipient to “[identify] a preferred donor among the plurality of donors”. For example, a woman could use it to select a sperm donor whose genes, combined with hers, are most likely to produce certain phenotypes in her baby. The phenotypes suggested range from eye colour to risk of diabetes to lifespan.

Eugenics fears

The ability to choose preferred donors worries ethicists. Although screening for disease is ethical, using DNA to select other characteristics edges close to eugenics, says Michael Sandel of Harvard University.

Lori Andrews, a law and technology expert at Chicago-Kent College of Law at the Illinois Institute of Technology, says sperm and egg donors are already screened genetically for known medical risks.

But researchers have so far found only weak associations between specific DNA sequences and phenotypes, such as intelligence, governed by many genes. “Is there really sufficient proof of the ability to predict traits such as lifespan through genetic tests?” asks Andrews.

If not, choosing a sperm or egg donor on the basis of genes thought to be associated with various traits could raise false expectations. If a resultant baby lacks the traits the parents expected, says Hogarth, there is likely to be disappointment. That raises the spectre of liability.

That might explain why the company now says that it has no plans to utilise the patent beyond the Inheritance Calculator – which covers only phenotypes controlled entirely by one or two genes.

Cutler says the company’s plans changed in the five years since it filed for the patent. He could not say how they might change in future, when genetic researchers hope to have found more reliable associations between genes and phenotypes.