Examining the uptake of predictive BRCA testing in the UK; findings and implications

Predictive BRCA testing is offered to asymptomatic individuals to predict future risk where a variant has been identified in a relative. It is uncertain whether all eligible relatives access testing, and whether this is related to health care inequalities. Our aim was to analyse trends and inequalities in uptake of testing, and identify predictors of testing and time-to-receipt of testing. A database from April 2010 to March 2017 was collated. Multivariate analysis explored individual associations with testing. Predictor variables included gender, BRCA test type, cancer history, Index of Multiple Deprivation (IMD) and education status. To evaluate factors associated with time-to-testing, a Cox proportional-hazards (CP) model was used. Of 779 tests undertaken, 336 (43.1%) were identified with a BRCA variant. A total of 537 (68.9%) were female and in 83.4% (387/464) of probands, predictive testing was received by relatives. Analysis identified inequalities since decreased testing was found when the proband was unaffected by cancer (OR 0.14, 95% CI 0.06-0.33). Median time-to-testing was 390 days (range, 0-7090 days) and the CP model also identified inequalities in the hazard ratio (HR) for testing for people aged >40 was higher than for aged <40 (HR 1.41, 95% CI 1.20-1.67) and BRCA2 testing was higher than for BRCA1 testing (HR 1.39, 95% CI 1.18-1.64). Reduced testing was found when probands were unaffected by cancer and time-to-testing was found to vary by age and BRCA1/2 test. Given limited study sample size, further research is recommended to examine inequalities in predictive BRCA testing.

Web-based return of BRCA2 research results: one-year genetic counselling experience in Iceland

There is an increased pressure to return results from research studies. In Iceland, deCODE Genetics has emphasised the importance of returning results to research participants, particularly the founder pathogenic BRCA2 variant; NM_000059.3:c.771_775del. To do so, they opened the website www.arfgerd.is . Individuals who received positive results via the website were offered genetic counselling (GC) at Landspitali in Reykjavik. At the end of May 2019, over 46.000 (19% of adults of Icelandic origin) had registered at the website and 352 (0.77%) received text message informing them about their positive results. Of those, 195 (55%) contacted the GC unit. Additionally, 129 relatives asked for GC and confirmatory testing, a total of 324 individuals. Various information such as gender and age, prior knowledge of the variant and perceived emotional impact, was collected. Of the BRCA2 positive individuals from the website, 74 (38%) had prior knowledge of the pathogenic variant (PV) in the family. The majority initially stated worries, anxiety or other negative emotion but later in the process many communicated gratitude for the knowledge gained. Males represented 41% of counsellees as opposed to less than 30% in the regular hereditary breast and ovarian (HBOC) clinic. It appears that counselling in clinical settings was more reassuring for worried counsellees. In this article, we describe one-year experience of the GC service to those who received positive results via the website. This experience offers a unique opportunity to study the public response of a successful method of the return of genetic results from research.

Genomic profiling of 553 uncharacterized neurodevelopment patients reveals a high proportion of recessive pathogenic variant carriers in an outbred population

A substantial portion of Mendelian disease patients suffers from genetic variants that are inherited in a recessive manner. A precise understanding of pathogenic recessive variants in a population would assist in pre-screening births of such patients. However, a systematic understanding of the contribution of recessive variants to Mendelian diseases is still lacking. Therefore, genetic diagnosis and variant discovery of 553 undiagnosed Korean patients with complex neurodevelopmental problems (KND for Korean NeuroDevelopmental cohort) were performed using whole exome sequencing of patients and their parents. Disease-causing variants, including newly discovered variants, were identified in 57.5% of the probands of the KND cohort. Among the patients with the previous reported pathogenic variants, 35.1% inherited these variants in a recessive manner. Genes that cause recessive disorders in our cohort tend to be less constrained by loss-of-function variants and were enriched in lipid metabolism and mitochondrial functions. This observation was applied to an estimation that approximately 1 in 17 healthy Korean individuals carry at least one of these pathogenic variants that develop severe neurodevelopmental problems in a recessive manner. Furthermore, the feasibility of these genes for carrier screening was evaluated. Our results will serve as a foundation for recessive variant screening to reduce occurrences of rare Mendelian disease patients. Additionally, our results highlight the utility and necessity of whole exome sequencing-based diagnostics for improving patient care in a country with a centralized medical system.

Monoallelic MUTYH carrier status is not associated with increased breast cancer risk in a multigene panel cohort

Whether monoallelic MUTYH mutations increase female breast cancer risk remains controversial. This study aimed to determine if monoallelic MUTYH mutations are associated with increased breast cancer risk in women undergoing multigene panel testing (MGPT). The prevalence of monoallelic MUTYH mutations was compared between Non-Hispanic white female breast cancer cases (n = 30,456) and cancer-free controls (n = 12,289), all of whom underwent MGPT that included MUTYH. We tested breast cancer associations with MUTYH alleles using Fisher's exact test, followed by multivariate logistic regression adjusted for age at testing and MGPT type ordered. Frequencies of the two most common MUTYH founder mutations, p.G396D and p.Y179C, were compared independently between the breast cancer cases and MGPT controls, as well as the healthy UK10K control population (n = 2640). Comparing cases to MGPT controls, no association was observed between female breast cancer and any monoallelic MUTYH carrier status (OR 0.86-1.36, p = 0.21-0.96). Similarly, comparisons to UK10K controls revealed no significant increase in breast cancer risk associated with p.G396D (OR 1.20, p = 0.44) or p.Y179C (OR 1.71, p = 0.24). This study did not find a significant increase in breast cancer risk associated with monoallelic MUTYH mutations.

Frequency of carrier screening and preventive orientation among first degree relatives of Thalassaemia patients

OBJECTIVE

To get preliminary data regarding the prevention of thalassaemia major in future generations.

METHODS

This Knowledge Attitude Practices study was conducted at Pakistan Institute of Medical Sciences, Islamabad, Pakistan, from January to June 2016, using non-probability purposive sampling. Parents of children undergoing transfusion were interviewed. Questionnaires were used to collect demographics and data about awareness, attitude and frequency of screening among the first degree relatives of a thalassaemia major patient. SPSS 20 was used for data analysis.

RESULTS

Of the 270 respondents 240(88.9%) had utilised screening services for their asymptomatic children and had a positive attitude towards prevention, but 30(11.1%) families did not screen asymptomatic children for thalassaemia minor. Besides, 49(18.1%) families had more than one thalassaemia major child in their nuclear family, while, 3(1.1%) were unwilling to let their children undergo tests. Nine (3.3%) respondents said they will not ask a prospective daughter/son-in-law to get tested for thalassaemia minor, while 194(71.9%) respondents had had cousin marriages.

CONCLUSIONS

There were significant gaps in awareness among affected families.

Highlighting the impact of cascade carrier testing in cystic fibrosis families

BACKGROUND

Cascade carrier testing within cystic fibrosis (CF) affected families offers relatives of CF patients the opportunity to know their status regarding the mutation that segregates within their family, and thus to make informed reproductive choices. As an Australian study has recently shown that this test seemed underused, we searched to assess uptake of this test in a European area where CF is common, and to report its public health implications.

METHODS

This study relied on 40 CF-affected families from western Brittany, France. Investigations included drawing of family trees and registration of carrier tests performed in those families.

RESULTS

Of the 459 relatives eligible for testing, 185 were tested, leading to an adjusted uptake rate of testing of 40.7% (95% CI: [34.1%; 47.3%]). The main predictors for having testing were being female (p=0.031) and having a high prior risk (p<0.001). Planning a pregnancy or expecting a child (reported in at least 38.4% of tested relatives) also appeared critical in choosing to be tested. Overall, carrier testing allowed to reassure more than 1/4 of the relatives and to detect five new 1-in-4 at-risk couples who then requested prenatal diagnosis.

CONCLUSIONS

This observational study assesses, for first time in Europe, uptake of CF cascade carrier testing within CF families, which is a critical tool to reassure non-carriers and to detect early new at-risk couples.