One of the profound ironies of modern science is that no social group is better equipped either in its ability to provide reliable, ordered health data or in its capacity to interpret its genetic and medical implications than the Jewish community. At the same time, no group has greater reason to be wary of the way in which such implications can be misused.

That issue has now prompted some leaders of the US Jewish community to seek reassurance that research data from studies of particular ethnic groups are not used to those groups' disadvantage (see page 322). Their concern is that the publicity surrounding recent research — such as last year's discovery of a significant proportion of a particular breast cancer mutation among Ashkenazi Jews in the United States, and similar recent findings related to colon cancer — may indirectly create problems for members of that group, for example in obtaining adequate health insurance cover.

Several important points need to be remembered. One is that a high incidence of a particular mutation does not necessarily imply a high incidence of the related disease; other, perhaps environmental or psychological, factors may be equally important. The second is that, for understandable reasons of research methodology, most recent genetic ‘discoveries’ have been associated with wellstructured — and often geographically isolated — social groups, such as the inhabitants of Tristan da Cunha (asthma), Iceland (familial essential tremor) and Finland (diastrophic dysplasia).

Unsurprisingly, the diseases chosen for study in these groups tend to be those with a significantly higher presence than in the rest of the population. But the attractiveness of searching for other genetic clues in these same populations should not blind researchers to the potential risks. The real challenge is eliminating the stigma still attached to the concept of ‘mutant’. This is a question partly of education, partly of legislation (for example, banning genetic discrimination in insurance and employment). If the flag raised by the Jewish community helps to speed either process, it will have achieved a worthwhile goal.