Predictive testing of minors for Huntington's disease: The UK and Netherlands experiences.

A consistent feature of predictive testing guidelines for Huntington's disease (HD) is the recommendation not to undertake predictive tests on those < 18 years. Exceptions are made but the extent of, and reasons for, deviation from the guidelines are unknown. The UK Huntington's Prediction Consortium has collected data annually on predictive tests undertaken from the 23 UK genetic centers. DNA analysis for HD in the Netherlands is centralized in the Laboratory for Diagnostic Genome Analysis in Leiden. In the UK, 60 tests were performed on minors between 1994 and 2015 representing 0.63% of the total number of tests performed. In the Netherlands, 23 tests were performed on minors between 1997 and 2016. The majority of the tests were performed on those aged 16 and 17 years for both countries (23% and 57% for the UK, and 26% and 57% for the Netherlands). Data on the reasons for testing were identified for 36 UK and 22 Netherlands cases and included: close to the age of 18 years, pregnancy, currently in local authority care and likely to have less support available after 18 years, person never having the capacity to consent and other miscellaneous reasons. This study documents the extent of HD testing of minors in the UK and the Netherlands and suggests that, in general, the recommendation is being followed. We provide some empirical evidence as to reasons why clinicians have departed from the recommendation. We do not advise changing the recommendation but suggest that testing of minors continues to be monitored.

Client views and attitudes to non-invasive prenatal diagnosis for sickle cell disease, thalassaemia and cystic fibrosis.

In the near future the availability of non-invasive prenatal diagnosis (NIPD) for single gene disorders will change the prenatal diagnosis options available to couples who are carriers of conditions such as cystic fibrosis, sickle cell disorder and thalassaemia. Client opinions about NIPD are needed to inform the implementation of NIPD for single gene disorders. This qualitative study used two focus groups (n = 12) and one-to-one interviews (n = 16) with carriers and support group representatives of sickle cell disease, thalassaemia and cystic fibrosis. Discussions were digitally recorded, transcribed verbatim and analysed using thematic analysis. Opinions about NIPD were very positive and participants valued the opportunity to have safe and early testing. Uptake of prenatal testing is likely to increase as women who had previously declined invasive testing expressed interest in having NIPD. Participant concerns about NIPD centred on the need for accuracy to be high to be used for subsequent decision making about termination of pregnancy. Participants also raised concerns that less thought may be given to having a blood test compared to an invasive test and that the perceived ease of a blood test may bring increased pressure to have testing. Participants thought NIPD should be offered through existing specialist services to ensure appropriate genetic counseling and support. Maintaining all testing options is important as some people may prefer invasive testing over NIPD if invasive testing was more accurate or if invasive testing could give information about other conditions such as Down syndrome.

Long-term evaluation of genetic counseling following false-positive newborn screen for cystic fibrosis.

This cross-sectional mixed method study was a long-term follow-up evaluation of families who participated in an earlier survey of their understanding of cystic fibrosis (CF) genetics and their infants' false-positive CF newborn screening (NBS) results. Thirty-seven of the original 138 parents participated in the follow-up telephone survey. Results showed parents who received genetic counseling at the time of their infants' diagnostic sweat tests had significantly higher long-term retention of genetic knowledge than those without genetic counseling. However, both groups still had misconceptions and lacked accurate information about the actual risk associated with being a CF carrier. Most parents either had already informed (65%) or planned to inform (19%) their children about the child's carrier status. Mean child age at the time of disclosure was 9.2 years. Situational prompts were the most common reasons for informing their children. Neither parental knowledge, medical literacy, nor parental education predicted whether parents informed their children about their carrier status. False-positive NBS results for CF were not associated with parental perceptions of child vulnerability 11-14 years after the testing. Although the sample from this study was small, these findings underscore the benefits of genetic counseling at the time of the diagnostic sweat test and offer information that can assist parents in talking with their children about the implications of having one CFTR mutation.