Cascade carrier testing after a child is diagnosed with cystic fibrosis through newborn screening: investigating why most relatives do not have testing.

PURPOSE

Newborn screening for cystic fibrosis is increasingly available, but cascade testing following the diagnosis in a child has received little attention. We previously reported low levels of cascade testing over time, and this study investigated motivators as well as barriers to testing.

METHODS

Parents were interviewed about communicating the genetic information and also asked to recruit their relatives to receive a specifically developed questionnaire.

RESULTS

Thirty parents were interviewed and addresses of 284 relatives were provided; completed questionnaires were received from 225 (79%). A relative's relationship to the child, as well as knowledge, is associated with having had carrier testing. Relatives' reasons for testing included curiosity and wanting information for other relatives and for reproductive planning. Reasons for not testing were perceived irrelevance, lacking awareness, and viewing it as something to do in the future. Parents communicated the genetic information to relatives in various ways, which contributed to whether relatives accessed carrier testing.

CONCLUSION

Newborn screening programs should provide support to parents to aid communication of genetic information to relatives. (Ir)relevance of testing is often linked to life stage; ongoing support and communication may allow relatives to learn of their risk and then seek testing, if they wish, at a time perceived to be most relevant to them.