About us Our team Dr Yvonne Wren I am a research speech and language therapist with a specific interest in cleft. I lead the national cohort study, the Cleft Collective, which is investigating the causes, treatments and outcomes for people born with cleft lip and/or palate. We are recruiting from all 16 regional cleft sites in the UK and have over 9000 participants. We are collecting biological samples for genotyping, parent questionnaires for information on children’s development and both child and parent well-being, clinical data direct from the 16 sites as well as linking to education and health data. The data collected are available for the international research community to access and use to address questions which will impact on clinical care and outcomes.