In their recent Commentary (Nature 418, 585–586; 2002), R. Williamson and R. Duncan discuss the use of universal neonatal DNA screening for forensic purposes. Such an approach would take a huge investment for at least 20–30 years before showing any benefit in terms of crime prevention. It also seems bizarre to treat each individual as likely to commit a serious crime from the time of birth!
Free DNA testing for all is essential, but for very different reasons. In most cultures, at least a small percentage of children are born through infidelity. Added to that, as many as 10% of couples now use assisted reproduction, often involving the use of gametes from unknown donors. Children born through such practices are likely to be of similar age and to grow up in the same area. A significant percentage of couples may, unknowingly, be closely related.
These serious problems have not received sufficient attention, and are likely to be contributing to the birth of children with serious genetic conditions. It is therefore essential that the availability of wider reproductive choices in modern society should be coupled to education about the risks of consanguinity and the provision of free DNA testing for all people of reproductive age, competently administered by an independent authority under strict regulations. This would empower every couple to make an informed choice, based on their genetic relatedness, on whether to proceed with childbearing or to seek alternative solutions. Such a service will result in immediate benefits for both the participating individuals and society at large.
The information acquired through consanguinity testing should be archived by the testing authority to facilitate long-term follow-up. The consanguinity database could be made accessible to the police authorities searching for matches with samples taken from crime scenes, but the identity of any positive samples should be revealed to the police authorities only after proper, independent authorization.
Consanguinity testing can thus complement DNA profiling of convicted individuals by police authorities, without the negative connotations of neonatal DNA screening.