5 December 2005
Senior Research Fellow, Centre for Research in Primary Care, University of Leeds
Appeared in BioNews 337The recent Newsnight programme (broadcast on BBC2, on 16 November) on cousin marriage attempted to deal with a complex health issue, involving the marriage preference of a minority ethnic group, genetic risk, lay and professional understanding of this risk and the attempts to deal with it. Genetics is a relatively new scientific field with professionals and the public still in the initial stages of reacting to individual and societal implications of possible genetic risk. The programme provided a snapshot of society in that initial stage. It's predominant focus on reporting perceptions of a social practice as problematic, rather than genetic advances that will allow families to make informed choices, is a reflection of how the dominant culture continues to deal with minority ethnic health. Locating the cause and solution to minority health issues within the cultural practices of those communities is well-documented. This ongoing approach serves to shift responsibility for the resolution of health issues from policy makers to individuals and communities; it continues to alienate minority ethnic communities and hampers the process of devising responsive services for our multiethnic population.
The view that likens cousin marriage to lifestyle issues underestimates the complex emotional and social rationale for why and how people make choices about life partners - to assume that it is blind adherence to tradition is a simplification. The complexity is more akin to that involved in women making choices about if, and when to have children in the present socio-economic context. The risk of Down syndrome increases considerably with advancing maternal age and a woman's decision to have children in her early twenties, based on health risk alone, would require a serious analysis of how that decision would impact on her life emotionally, economically and socially. In recognition of a woman's right to informed choice the NHS offers responsive services tailored to the needs of modern women.
But to date, the predominant focus of media attention has been on alarmist presentation of data on the increased prevalence of recessive disorders in the British Pakistani community, with little consideration of other pertinent issues. British Pakistanis are not alone in their preference for cousin marriage; globally at least 20 per cent of the human population live in communities with a preference for consanguineous marriage and 8.5 per cent of all births are to consanguineous parents. Improvements in public health, better general healthcare and the consequent lower rates of infant mortality mean that children with serious genetic conditions are now surviving, particularly in higher resource countries. The development of appropriate genetic and preventative services, responsive to diverse marriage preferences, is a global as well as a national challenge.
Marriage between two individuals who are cousins, in itself, is not the cause of recessive conditions. It simply increases the prevalence of very rare recessive conditions in a population, as cousins are more likely to be carriers of the same recessive gene variant. In the British Pakistani population a minority of couples are likely to be carriers, while the vast majority of couples do not have any additional risk. Although population statistics play an important role in service planning, they are of limited value to individuals in making decisions, for whom only precise risk based on their carrier status and family history is relevant. Alarmist messages, based on population statistics that link cousin marriage, per se, with inherited conditions are both confusing and counterproductive. There are documented cases of couples who disbelieve the messages because they are surrounded by others in their families who are cousins but have healthy children, plus white couples who do not marry cousins but have children with disabilities.
The required response is for carrier detection plus adequate genetic counselling facilities that allow people to make informed choices, based on accurate information about their individual risk; available data shows that information and support to at-risk British Pakistani families is grossly deficient. A population approach that focuses on altering a whole community's marriage pattern is an inadequate and superficial response to a serious health issue.
Recent advances in genetic diagnosis mean that at-risk couples can be offered genetic testing for over 40 per cent of recessive conditions; this number is likely to increase rapidly in the near future. Epidemiological findings show that manifestation of recessive conditions as clusters within communities with a preference for consanguineous marriage, rather than sporadically throughout the population, greatly simplifies the process of identifying clusters of carriers of recessive variant genes in these communities.
In the UK, this health issue is particularly conspicuous in areas of high British Pakistani settlement. A concerted focus on detecting at-risk families and the provision of adequate genetics facilities in these areas, would be a far more ethical and inclusive approach for a multiethnic society, committed to equity in service delivery.