"They don't know how to live with a child with these conditions, they can't understand...": The lived experiences of parenting a child with a genetic neurodevelopmental disorder.

Background: A genetic neurodevelopmental diagnosis (GND) impacts all aspects of a child and family's life. GNDs are rare; most have limited natural history data. We aimed to understand parents' experiences around data acquisition about their child's GNDs which can help inform clinical practice. Design and participants: This analysis is part of the UK multicentre GenROC study. We conducted 17 semi-structured interviews with parents of children with GNDs (aged 0-15 years). Data were analysed following the principles of thematic analysis. Results: Five main themes are reported: Impact on the family around a genetic diagnosis: Distress results from diagnosis wait, the act of receiving it, associated irreversibility (loss of hope) and family/reproductive implications. GNDs and Uncertainty: Lack of data and rareness causes uncertainty for the future. Relationships with health professionals: Positive where parents are empowered and feel part of the team; Negative-parents feel not heard/believed or lack of expertise/understanding. Parent mental health: GNDs can be a significant burden to family life. Need for advocating for services is a negative impact. Isolation through rareness is a factor - this can be helped by support networks which mostly consist of gene specific Facebook groups. Development of positive parent identities: including that of advocate, professional and educator. Conclusions GNDs represent a major challenge for families, clinicians and service providers. Distressed parents are struggling to cope with challenges and suffer poor mental health. Psychosocial support, better signposting, and health professional education may help. Patient contribution PPI group contributed to topic guide development and commented on findings.