Rapid genomic sequencing (RGS) is increasingly being used in the care of critically ill children. Here we describe a
qualitative study exploring parent and professional perspectives around the usefulness of this test, the potential for
unintended harms and the challenges for delivering a wider clinical service. The Rapid Paediatric Sequencing (RaPS) study
offered trio RGS for diagnosis of critically ill children with a likely monogenic disorder. Main and actionable secondary
findings were reported. Semi-structured interviews were conducted with parents of children offered RGS (n = 11) and
professionals (genetic clinicians, non-genetic clinicians, scientists and consenters) (n = 19) by telephone (parents n = 10/
professionals n = 1) or face-to-face (parents n = 1/professionals n = 18). We found that participants held largely positive
views about RGS, describing clinical and emotional benefits from the opportunity to obtain a rapid diagnosis. Parental stress
surrounding their child’s illness complicates decision making. Parental concerns are heightened when offered RGS and
while waiting for results. The importance of multidisciplinary team working to enable efficient delivery of a rapid service
was emphasised. Our findings give insight into the perceived value of RGS for critically ill children. Careful pre-test
counselling is needed to support informed parental decision making. Many parents would benefit from additional support
while waiting for results. Education of mainstream clinicians is required to facilitate clinical implementatio