Purpose KBG syndrome (KBGS) is a rare neurodevelopmental syndrome. We aimed to study the impact of KBGS in adulthood as reported by individuals with KBGS and their families/caregivers, thereby exploring aspects of everyday life under-reported by healthcare professionals. Methods We co-produced an online questionnaire for adults with KBGS and their families/caregivers. Participants were recruited via the KBG foundation, an American based charity supporting individuals with KBGS and their families worldwide, and other international collaborators. Results There were 91 responses for analysis, across the age range of 16-86 years. Respondents described a range of living arrangements, education, employment, leisure activities and relationships. A higher proportion of 45-54year olds had achieved independent living skills such as driving and grocery shopping compared to the younger age groups. None of the participants who were experiencing seizures lived independently. We described high rates of psychiatric comorbidities, behavioural difficulties, sleep problems, seizures, visual and hearing problems, dental and skeletal issues, and a higher than expected cardiovascular and gastrointestinal burden of disease. Conclusion This study provides new insights into the everyday life of adults with KBGS, along with high rates of comorbidities which continue to impact on quality of life into adulthood, with implications for medical care.

The authors have declared no competing interest.

Allan Bayat is funded by a BRIDGE -Translational Excellence Programme grant funded by the Novo Nordisk Foundation, grant agreement number: NNF20SA0064340. Karen Low is funded by an NIHR Doctoral research fellowship award: NIHR302303. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR, (Partner Name), NHS or the UK Department of Health and Social Care. Nuria C Bramswig is a member of the European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability ERN-ITHACA. ERN ITHACA is funded by the European Union, under the Grant Agreement nr. 101156387.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was approved by the faculty of health research ethics committee at the University of Bristol/UK, in November 2023 (ref 16025). Written informed consent was collected from all respondents prior to completing the questionnaire, using research protocols approved by the ethics committee at the University of Bristol. The data gathered via the questionnaire was designed to allow anonymity and confidentiality.

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