Several different companies now sell ‘DNA ancestry’ or ‘ethnicity’ testing kits via the internet. A small sample of a person's blood or saliva can be sent via the post, its DNA extracted and a panel of polymorphic genetic markers can be analysed. This information is then used to provide a breakdown of a person's ‘racial origins’ by categorising someone as a percentage of their ancestry that is African, East Asian, Native American or European. While these kits have proved very popular with adults interested in genealogy, we have recently become aware of their use in adoption and fostering cases in attempts to determine a child's ethnicity. We believe such use is inappropriate and indicates a misunderstanding of the concept of ethnicity and the technical limitations of such genetic tests. It is recommended that extreme caution must be exercised in their use for any adoption and fostering decisions.

The last few years have seen an explosion of companies offering ‘DNA ancestry’ or ‘ethnicity’ testing using a variety of polymorphic genetic markers. Several different companies offer to analyse a person's DNA from a blood or saliva sample and offer to provide a breakdown of ‘racial origins’ by categorising someone as a percentage of their ancestry that is African, East Asian, Native American or European. These tests have proved popular with those interested in genealogy and sales in the order of several tens of thousands in the UK and nearly half a million in the USA make this a profitable commercial exercise. More recently, several authors have urged caution in the interpretation and use of these tests, and an editorial in the journal Science1 called for others to make position statements outlining …