Noninvasive prenatal testing (NIPT) in Western Australia; considerations in clinical practice

Western Australian women's expectations for expanded NIPT-An online survey regarding NIPT for single gene, recessive and chromosomal conditions

Prenatal screening has evolved rapidly following the introduction of non-invasive prenatal testing (NIPT), with screening now available for an increasing number of conditions. We explored the attitudes and expectations of women within the context of using NIPT to detect multiple different single gene and chromosome conditions during pregnancy. An online survey was used to assess these issues with a sample of 219 women from Western Australia. In our study, the majority of women (96%) support of the concept of expanded NIPT for single gene and chromosome conditions provided the test involves no risk to the pregnancy and can provide the parents with relevant medical information about the fetus at any stage of pregnancy. 80% believed that expanded NIPT for single gene and chromosome conditions should be available at any stage during pregnancy and 68% of women indicated that test cost would be a factor in determining their participation in testing. Under half (43%) of the women favored an option to terminate a pregnancy at any stage if the fetus had a medical condition that would interfere with day to day functioning. The majority (78%) of women believed that testing for multiple genetic conditions would provide reassurance and lead to the delivery of a healthy child.

Women's responses to prenatal genetic diagnosis and attitudes to termination of pregnancy after non-invasive prenatal testing: An online survey of Western Australian women

BACKGROUND

Non-invasive prenatal testing (NIPT) using cell-free DNA (cfDNA) has expanded from detecting chromosome aneuploidy to testing for a variety of genetic conditions, including some select single gene disorders. As next generation sequencing/whole exome sequencing technology develops, it may be possible to expand NIPT of cfDNA to identify hundreds of single gene and chromosomal disorders in a fetus, thereby increasing the complexity of pretest counselling and parental decision-making.

AIM

The aim of this study was to assess the views of women on the phenotypes of genetic conditions potentially detectable with expanded NIPT that they would consider severe enough to warrant pregnancy termination.

MATERIALS AND METHODS

Using multiple clinical scenarios, we asked women via an online survey about the early detection of several well-described genetic phenotypes in pregnancy that in theory could be detected by expanded NIPT.

RESULTS

Two hundred and nineteen women participated in this study. There was high support for early diagnosis and the option for termination of pregnancy in conditions perceived as severe (52-71%). Women expressed a preference for testing to be provided by general practitioners and assigned a high value to genetic counselling support (75-90%). In the case of a continuing pregnancy, women recognised the essential role of ongoing psychosocial counselling for family members and childhood early intervention programs.

CONCLUSION

Women expressed clear preferences for termination of pregnancy for severe conditions and as early in gestation as feasible. Information and support from genetic counsellors are a highly valued resource in decision-making following a prenatal diagnosis of a fetal genetic abnormality.

Current Genetic Service Delivery Models for the Provision of Genetic Testing in Europe: A Systematic Review of the Literature

Background: The provision of genetic services, along with research in the fields of genomics and genetics, has evolved in recent years to meet the increasing demand of consumers interested in prediction of genetic diseases and various inherited traits. The aim of this study is to evaluate genetic services in order to identify and classify delivery models for the provision of genetic testing in European and in extra-European countries. Methods: A systematic review of the literature was conducted using five electronic resources. Inclusion criteria were that studies be published in English or Italian during the period 2000-2015 and carried out in European or extra-European countries (Canada, USA, Australia, or New Zealand). Results: 148 genetic programs were identified in 117 articles and were delivered mostly in the UK (59, 40%), USA (35, 24%) or Australia (16, 11%). The programs were available nationally (66; 45%), regionally (49; 33%) or in urban areas (21, 14%). Ninety-six (64%) of the programs were integrated into healthcare systems, 48 (32.21%) were pilot programs and five (3%) were direct-to-consumer genetic services. The genetic tests offered were mainly for BRCA1/2 (59, 40%), Lynch syndrome (23, 16%), and newborn screening (18, 12%). Healthcare professionals with different backgrounds are increasingly engaged in the provision of genetic services. Based on which healthcare professionals have prominent roles in the respective patient care pathways, genetic programs were classified into five models: (i) the geneticists model; (ii) the primary care model; (iii) the medical specialist model; (iv) the population screening programs model; and (v) the direct-to-consumer model. Conclusions: New models of genetic service delivery are currently under development worldwide to address the increasing demand for accessible and affordable services. These models require the integration of genetics into all medical specialties, collaboration among different healthcare professionals, and the redistribution of professional roles. An appropriate model for genetic service provision in a specific setting should ideally be defined according to the type of healthcare system, the genetic test provided within a genetic program, and the cost-effectiveness of the intervention. Only applications with proven efficacy and cost-effectiveness should be implemented in healthcare systems and made available to all citizens.

Systematic review and meta-analysis of non-invasive prenatal DNA testing for trisomy 21: implications for implementation in China

OBJECTIVES

To systematically review clinical validation studies of massive parallel sequencing (MPS) technology in prenatal screening for trisomy 21 and to explore the potential implementation strategies in China compared with those in developing countries.

METHODS

Searches of the Cochrane Library, Medline, EMBASE, Web of Science, Biosis Previews, and three major Chinese databases were performed to identify all the peer-reviewed articles published between 1 January 2011 and 15 October 2016. We also reviewed and discussed the potential challenges and risks in the future promotion of MPS technology in China compared with those in developing countries.

RESULTS

The weighted pooled sensitivity and specificity of MPS technology for the prenatal detection of trisomy 21 were 99.7% (95% CI 98.3-99.9%) and 100.0% (95% CI 99.9-100.0%), respectively, based on a meta-analysis of 44 included studies. An additional meta-analysis was conducted based on the 25 included studies that were performed in medical/genetic sequencing institutions in mainland China, showing a weighted pooled sensitivity and specificity of MPS technology as 99.5% (95% CI 98.7-99.8%) and 100% (95% CI 99.9-100%), respectively.

CONCLUSION

MPS technology offers effective screening performance for trisomy 21 but should be cautiously promoted due to its clinical limitations and challenges that stem from the ethics and business aspects. © 2017 John Wiley & Sons, Ltd.