10,000 families have been recruited in one of the most ambitious studies of children's health ever undertaken in the world. Bradford has twice the national rate of infant mortality and the highest rate of genetic illness in Britain. Overall sixty per cent of births in the city are to families living amongst the poorest twenty per cent of those in the UK. Bradford tops the national tables for heart disease, strokes and diabetes Over half of the 6,000 babies born in the city every year are to Pakistani mothers and two thirds of these women are married to first or second cousins - which significantly increases the risk of autosomal recessive (i.e. genetic) conditions. Doctors have identified 147 of these different conditions in Bradford children, compared to between fifteen and twenty in other health districts. Many lead to severe disabilities and reduced life expectancy. According to the Head of the study, Professor John Wright, an epidemiologist based at Bradford Royal Infirmary, the aim is to find out more about the causes of childhood illness in newborns from all cultures and classes: "It's like a medical detective story really - trying to piece together the clues in people's lifestyles, their environments and their genetic make-up, as we try to determine whether someone falls sick or someone doesn't." Safina Nagvi and her sister, Tahira, are keen to support the research. Tahira has just given birth to her third child but has suffered various complications which she says might be linked to genetic problems: "we both married first cousins, and it is OK for us, it's not like we've been forced or we're unhappy - the way we've been brought up it is normal for us, we are happy with things that way. "But we have had things in our family, though. My son was born five weeks early. He had a condition where the gut and the stomach were joined together. I actually got a heart birth defect - they had to widen one of the arteries up. I also had the same problem that my son had when I was born and we would like to know why". According to Ann Barratt, the Family liaison officer for the project, one aspect of the study is people looking at why these things are happening: "we would like better understanding of some of these quite rare conditions you see in Bradford. One of the main reasons for the study was because the still birth rate was almost double the UK average a few years ago and that's one of the things we're looking at, why is the mortality rate higher.".