The Cleft Collective is a longitudinal cohort study looking to investigate the biological and environmental causes of cleft and the best treatments of cleft on those affected and their families. The study comprises two separate cohorts, a Birth Cohort and a 5-year-old Cohort. The birth cohort is further split into two sub-groups, postnatal and antenatal, allocation to these groups is determined by the time of recruitment. Recruitment to the two cohorts is currently ongoing across the UK. A large amount of phenotypic and environmental exposure data is being collected via questionnaires and record linkage. A data dictionary, available on the study website, contains details of all the available data.
As a minimum, biological mother and affected child are recruited to the study. Where possible, biological father or mother's partner is also recruited. In addition, the study aims to recruit unaffected and affected siblings for a small proportion of the cohort.
Biological samples are collected from all participants. Parents and siblings of both cohorts and affected children of the 5-year-old cohort provide saliva samples. Residual tissue and blood samples are collected from affected children recruited to the birth cohort. In addition, cord blood samples are collected from families recruited to the antenatal strand.