The British 1958 birth cohort is based on all persons born in Britain during one week in 1958. They were originally recruited for a perinatal mortality and morbidity survey and were followed through school years with medical examinations at ages 7, 11 and 16. Thereafter, biomedical information was limited to self-reported symptoms and medical histories obtained at ages 23, 33 and 42, although a subsample took part in a special study of asthma and allergy at age 34-35 which involved examination by a nurse in the home setting. The present study, at age 44-45, represents the first biomedical examination of most cohort members since childhood, and is the first occasion on which blood samples have been taken and stored.
Following a period of piloting, this fieldwork started in September 2002 and was completed in March 2004. The visits were carried out by a team of over 120 specially trained nurses from the National Centre for Social Research, who conduct the annual Health Surveys of England and Scotland. 9377 cohort members were visited, 78% of those invited to participate. Blood samples were collected from 88% of those examined, and 97% of these gave consent to creation of immortalised cell lines, extraction and storage of DNA for medical research purposes.
We received 8018 usable blood samples from subjects who gave consent to extraction of DNA, and 7692 usable blood samples from cohort members who also gave consent for creation of immortalised cell cultures. Successful EBV transformation was achieved for 7526 of these. DNA specimens have been directly extracted from all 8018 EDTA blood residues, and prepared from all 7526 transformed cell cultures. Both series are currently in use in collaborating laboratories, and DNA quality appears satisfactory. The standard issue is 1μg per well, at 50ng/μl, but larger quantities and concentrations are available on request.
Researchers seeking to use DNA from the 1958 cohort must apply to the oversight committee, specifying the nature of their case series, the candidate genotypes they propose to study, the genotyping method to be employed (plus evidence of quality control/accuracy) and the amount of DNA requested. The committee will consider such applications at suitable intervals, no less than twice a year. Approval is conditional upon the collaborators signing a Material Transfer Agreement (pdf) to provide a data file of all genotypic information obtained from the samples, for inclusion in a central database of 1958 cohort genetic data, to be held securely at St George's, University of London. This central database is the basis for the website presentation of allele and genotype frequencies.