Vascular Ehlers-Danlos Syndrome: A Comprehensive Natural History Study in a Dutch National Cohort of 142 Patients

BACKGROUND

Vascular Ehlers-Danlos syndrome (vEDS) is a rare connective tissue disorder with a high risk for arterial, bowel, and uterine rupture, caused by heterozygous pathogenic variants in COL3A1. The aim of this cohort study is to provide further insights into the natural history of vEDS and describe genotype-phenotype correlations in a Dutch multicenter cohort to optimize patient care and increase awareness of the disease.

METHODS

Individuals with vEDS throughout the Netherlands were included. The phenotype was charted by retrospective analysis of molecular and clinical data, combined with a one-time physical examination.

RESULTS

A total of 142 individuals (50% female) participated the study, including 46 index patients (32%). The overall median age at genetic diagnosis was 41.0 years. More than half of the index patients (54.3%) and relatives (53.1%) had a physical appearance highly suggestive of vEDS. In these individuals, major events were not more frequent (P=0.90), but occurred at a younger age (P=0.01). A major event occurred more often and at a younger age in men compared with women (P<0.001 and P=0.004, respectively). Aortic aneurysms (P=0.003) and pneumothoraces (P=0.029) were more frequent in men. Aortic dissection was more frequent in individuals with a COL3A1 variant in the first quarter of the collagen helical domain (P=0.03).

CONCLUSIONS

Male sex, type and location of the COL3A1 variant, and physical appearance highly suggestive of vEDS are risk factors for the occurrence and/or early age of onset of major events. This national multicenter cohort study of Dutch individuals with vEDS provides a valuable basis for improving guidelines for the diagnosing, follow-up, and treatment of individuals with vEDS.

Impact of genetic counseling strategy on diagnostic yield and workload for genome-sequencing-based tumor diagnostics

PURPOSE

Genome sequencing (GS) enables comprehensive molecular analysis of tumors and identification of hereditary cancer predisposition. According to guidelines, directly determining pathogenic germline variants (PGVs) requires pretest genetic counseling, which is cost-ineffective. Referral for genetic counseling based on tumor variants alone could miss relevant PGVs and/or result in unnecessary referrals.

METHODS

We validated GS for detection of germline variants and simulated 3 strategies using paired tumor-normal GS data of 937 metastatic patients. In strategy-1, genetic counseling before tumor testing allowed direct PGV analysis. In strategy-2 and -3, germline testing and referral for post-test genetic counseling is based on tumor variants using Dutch (strategy-2) or Europen Society for Medical Oncology (ESMO) Precision Medicine Working Group (strategy-3) guidelines.

RESULTS

In strategy-1, PGVs would be detected in 50 patients (number-needed-to counsel; NTC = 18.7). In strategy-2, 86 patients would have been referred for genetic counseling and 43 would have PGVs (NTC = 2). In strategy-3, 94 patients would have been referred for genetic counseling and 32 would have PGVs (NTC = 2.9). Hence, 43 and 62 patients, respectively, were unnecessarily referred based on a somatic variant.

CONCLUSION

Both post-tumor test counseling strategies (2 and 3) had significantly lower NTC, and strategy-2 had the highest PGV yield. Combining pre-tumor test mainstreaming and post-tumor test counseling may maximize the clinically relevant PGV yield and minimize unnecessary referrals.

Does a proactive procedure lead to a higher uptake of predictive testing in families with a pathogenic BRCA1/BRCA2 variant? A family cancer clinic evaluation

The uptake of genetic counseling and predictive genetic testing by family members at risk for hereditary tumor syndromes is generally below 50%. To address this issue, a new guideline was introduced in the Netherlands in 2019 that aims to improve the sharing of information within families. In addition to cascade screening supported by follow-up telephone calls with the proband, municipal records were accessed to allow the geneticist to contact at-risk family members directly. We evaluated this procedure in 32 families with a (likely) pathogenic germline BRCA1/BRCA2 variant diagnosed at our hospital between May 1, 2020, and July 31, 2021, comparing current uptake with outcomes achieved for 33 families diagnosed in 2014. Fifteen months after diagnostic testing of the proband, the uptake was 43% (120/277), comparable to the 44% (87/200) registered previously. Among a subgroup of women at 50% risk aged 25-75 years, 71% (47/66) were tested, comparable to an earlier uptake of 69% (59/86). Of the 34 at-risk relatives we contacted directly, 17 (50%) underwent predictive testing. In conclusion, we found no evidence that the new procedure leads to a substantially increased uptake. Future research should be primarily aimed at understanding intrafamilial communication barriers.

Reasons for being in favour of or against genome modification: a survey of the Dutch general public

STUDY QUESTION

What are the general public's reasons for being in favour of or against the use of genome modification for five potential applications?

SUMMARY ANSWER

Overall, 43 reasons for being in favour, 45 reasons for being against as well as 26 conditional reasons for the use of genome modification were identified.

WHAT IS KNOWN ALREADY

Various applications of somatic genome modification are progressing towards clinical introduction and several recent studies have reported on germline genome modification. This has incited a debate on ethical and legal implications and acceptability. There is a growing plea to involve the general public earlier on in the developmental process of science and (bio)technology including genome modification.

STUDY DESIGN SIZE DURATION

In April 2016, a cross-sectional survey was launched online among the Dutch general public. A documentary on genome modification on public television and calls in social media invited viewers and non-viewers, respectively, to participate.

PARTICIPANTS/MATERIALS SETTING METHODS

The questionnaire introduced five potential future applications of genome modification: modified wheat for individuals with gluten intolerance; somatic modification for individuals with neuromuscular diseases; germline modification to prevent passing on a neuromuscular disease; germline modification to introduce resistance to HIV; and germline modification to increase intelligence. Participants were asked to indicate whether and why they would make use of genome modification in these scenarios. The reasons mentioned were analysed through content analysis by two researchers independently. The proportion of respondents that was willing to modify was described per scenario and associations with respondent characteristics were analysed.

MAIN RESULTS AND THE ROLE OF CHANCE

The survey was completed by 1013 participants. Forty-three reasons for being in favour, 45 reasons for being against as well as 26 conditional reasons for the use of genome modification were identified. These could be categorized into 14 domains: safety of the individuals concerned; effectiveness; quality of life of the individuals concerned; existence of a clinical need or an alternative; biodiversity and ecosystems; animal homo sapiens (i.e. relating to effects on humans as a species); human life and dignity; trust in regulation; justice; costs; slippery slope; argument of nature; parental rights and duties; and (reproductive) autonomy. Participants' willingness to use genome modification was dependent on the application: most participants would eat modified wheat if gluten intolerant (74%), would use genome modification to cure his/her own neuromuscular disease (85%) and would apply germline modification to prevent passing on this neuromuscular disease (66%). A minority would apply germline modification to introduce resistance to HIV (30%) or increase intelligence (16%). Being young (odds ratio (OR) = 0.98 per year increase), being male (OR = 2.38), and having watched the documentary (OR = 1.82) were associated with being willing to apply genome modification in more scenarios.

LIMITATIONS REASONS FOR CAUTION

Inquiring for reasons through open questions in a survey allowed for a larger sample size and intuitive responses but resulted in less depth than traditional face-to-face interviews. As the survey was disseminated through social media, the sample is not representative of the overall Dutch population, and hence the quantitative results should not be interpreted as such.

WIDER IMPLICATIONS OF THE FINDINGS

Further public consultation and a more in-depth ethical and societal debate on principles and conditions for responsible use of (germline) genome modification is required prior to future clinical introduction.

STUDY FUNDING/COMPETING INTERESTS

Funded by the University of Amsterdam and University Medical Centre Utrecht. No conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable.

Personalized assent for pediatric biobanks

Pediatric biobanking is considered important for generating biomedical knowledge and improving (pediatric) health care. However, the inclusion of children’s samples in biobanks involves specific ethical issues. One of the main concerns is how to appropriately engage children in the consent procedure. We suggest that children should be involved through a personalized assent procedure, which means that both the content and the process of assent are adjusted to the individual child. In this paper we provide guidance on how to put personalized assent into pediatric biobanking practice and consider both the content and process of personalized assent. In the discussion we argue that the assent procedure itself is formative. Investing in the procedure should be a requirement for pediatric biobank research. Although personalized assent will require certain efforts, the pediatric (biobank) community must be aware of its importance. The investment and trust earned can result in ongoing engagement, important longitudinal information, and stability in/for the research infrastructure, as well as increased knowledge among its participants about research activity. Implementing personalized assent will both respect the child and support biobank research.

When Children Become Adults: Should Biobanks Re-Contact?

Noor Giesbertz and colleagues consider different re-contact policy designs that could be used by biobanks to obtain permission for the continued use of samples collected from children.

Clarifying assent in pediatric research

Assent is a relatively young term in research ethics, but became an often mentioned ethical requirement in current pediatric research guidelines. Also, the European Society of Human Genetics considers assent an important condition for the inclusion of children in biobanks. However, although many emphasize the importance of assent, few explain how they understand the concept and few have elaborated on the underlying grounds. In this paper, we will discuss the different underlying ethical principles of assent. In the first category, assent appears to be derived from informed consent. This understanding is grounded in respect for autonomy and protection against harm. We conclude that this interpretation of assent is not of added value as a majority of children cannot be considered competent to make autonomous decisions. In addition, other safeguards are more appropriate to protect children against harm. The grounds from the second category can be classified as engagement grounds. These grounds do justice to the specifics of childhood and are of added value. Furthermore, we argue that it follows that both the content and the process of assent should be adjusted to the individual child. This can be referred to as personalized assent. Personalized assent is an appeal to the moral responsibility and integrity of the researcher.

Inclusion of residual tissue in biobanks: opt-in or opt-out?

Residual samples are an important source of tissue for biobanks. They refer to leftover tissue that is obtained in the course of clinical care. Residual samples can be included through an opt-in method--that is, a person explicitly expresses consent to include residual tissue--or an opt-out method--that is, the tissue is stored unless a person explicitly refuses. At the moment there is a renewed interest in the appropriate method for the inclusion of residual samples in biobanks. The expansion of biobanks and rapid developments in biomedical research underscore the need to evaluate the proper procedure. In this article we revisit the arguments in favor and against opt-in and opt-out methods for residual tissue research. We conclude firstly that an opt-out method is only justifiable when certain conditions are met: (1) awareness has to be raised, (2) sufficient information has to be provided, and (3) a genuine possibility to object has to be offered. An opt-out procedure that fulfills these conditions can be called a "thick" opt-out method. As a consequence, the dichotomy between opt-in and opt-out is less stark than usually suggested, as both methods require a certain amount of effort. Secondly, we conclude that because of the diversity of tissue and research, not every situation can be treated alike. There are at least four situations that require opt-in procedures: (1) research with higher risks or increased burdens, (2) the use of controversial or high-impact techniques, (3) research on sensitive tissue types, and (4) research involving vulnerable patients. We suggest that further interdisciplinary debate should answer the question when to opt-in or when to opt-out.