Risks to offspring of consanguineous marriage: we need straight, not crooked thinking.

1 have responded to the recurrent debates in the UK media about the pros and cons of cousin marriage? 2–5 He would surely have examined the key facts (Table 1), as well as exposing any dishonest tricks of an argument; he would also have pointed out that it is wise to avoid language which alienates some participants. A senior UK scientist recently spoke about first cousin marriages 2 , and referred to 'inbreeding', a term which has a specific scientific meaning. Physicians wishing to engage positively with patients who are first cousins should avoid the term. The data which led to criticism of the practice of cousin marriage in the media were collected in the Bradford area and earlier in Birmingham. In Bradford, the rate of cousin marriage in British citizens of Pakistani origin is around 75% and this community has a higher rate of congenital abnormalities, compared with the wider UK population. 12 The lay press focused on these two facts, suggesting that cousin marriage causes congenital anomalies. Few articles mentioned that the families involved came from a country where birth abnormalities are more common (in Pakistan, the infant mortality rate was 57.4 per 1,000 births last year, compared with the UK average of less than 5 per 1,000 13). Some of the greater neonatal morbidity and mortality is explained by the high incidence in Pakistan (around 1 person in 400) of the autosomal recessive (AR) disorder, beta-thalassaemia or by non-genetic causes (such as less access to obstetric care). But might these communities have higher rates of mutation? The danger of arguing that the problems will resolve if all communities cease to marry first cousins is that if gene mutations in the population (including AR genes) occur at a higher rate, then other marriages within that community will be at increased risk, as for the haemoglobinopathies. Eye-catching headlines may stigmatise cousin marriage or even reduce consanguinity, but this consequence alone may not significantly reduce the burden of early inherited disorders. This editorial is to guide physicians who wish to handle questions about genetic risks associated with consanguinity. If doctors establish the medical facts of each situation and apply genetic principles, mindful of socio-cultural factors, they will facilitate decision-making by their patients and improve insights within the community. Our backgrounds differ but there are many issues on which we have total agreement; firstly, that to criticise families who choose cousin …