Objective: This study summarises the diagnostic validity and clinical utility of genetic testing for patients with hypertrophic cardiomyopathy (HCM) and their at-risk relatives. Methods: A systematic search was performed in PubMed (MEDLINE), Embase, CINAHL and Cochrane Central Library databases from inception through 2 March 2020. Subgroup and sensitivity analyses were prespecified for individual sarcomere genes, presence/absence of pathogenic variants, paediatric and adult cohorts, family history, inclusion of probands, and variant classification method. Study quality was assessed using the Newcastle-Ottawa tool. Results: A total of 132 articles met inclusion criteria. The detection rate based on pathogenic and likely pathogenic variants was significantly higher in paediatric cohorts compared with adults (56% vs 42%; p=0.01) and in adults with a family history compared with sporadic cases (59% vs 33%; p=0.005). When studies applied current, improved, variant interpretation standards, the adult detection rate significantly decreased from 42% to 33% (p=0.0001) because less variants met criteria to be considered pathogenic. The mean difference in age-of-onset in adults was significantly earlier for genotype-positive versus genotype-negative cohorts (8.3 years; p<0.0001), MYH7 versus MYBPC3 cohorts (8.2 years; p<0.0001) and individuals with multiple versus single variants (7.0 years; p<0.0002). Overall, disease penetrance in adult cohorts was 62%, but differed significantly depending on if probands were included or excluded (73% vs 55%; p=0.003). Conclusions: This systematic review and meta-analysis is the first, to our knowledge, to collectively quantify historical understandings of detection rate, genotype-phenotype associations and disease penetrance for HCM, while providing the answers to important routine clinical questions and highlighting key areas for future study.
Laboratory genetic counseling is becoming increasingly common as a result of increased laboratory services and genetic testing menus, as well as growing job responsibilities. Christian et al. (2012) provided the first quantitative data regarding the roles of the laboratory‐based genetic counselor (LBGC) finding that two of the most prevalent roles are as customer liaisons and communicators of test results. The goal of the present study was to further delineate the role of the LBGC by addressing specific tasks that LBGCs are involved with on a day‐to‐day basis. A survey was designed to expand upon themes identified in the Christian et al. (2012) study by querying specific tasks performed in several categories of potential LBGC job duties. An invitation for LBGCs to participate was distributed via email to the membership of the National Society of Genetic Counselors (NSGC) and the Canadian Association of Genetic Counsellors (CAGC). We identified 121 genetic counselors who primarily work in the laboratory setting or whose job role includes a laboratory component. Almost all respondents performed customer liaison/case coordination (95 %), and interpretation and result reporting (88 %). The most frequently performed tasks within these categories involved addressing questions from clients, making phone calls with genetic testing results, obtaining clinical or family history information for results interpretation, and composing case‐specific interpretations for unique results and/or obtaining literature references to support interpretations. The study results also point to trends of expanding roles in sales and marketing, variant interpretation and management responsibilities. Results of this study may be useful to further define the full scope of practice of LBGCs, aid in the development of new LBGC positions and expand current positions to include roles related to test development, research, and student supervision. It may also aid in curriculum updates for training programs to increase exposure to LBGC roles.
An increasing number of genetic counselors are moving into non‐clinical roles, where their primary duties do not involve direct patient contact. According to the National Society of Genetic Counselors Professional Status Survey in 2010, 23% of counselors working in non‐clinical roles identified laboratory or genetic testing as their primary area of work. Using a survey, we identified 43 genetic counselors who work predominately in laboratory settings. The two primary tasks performed by participants, include acting as a customer liaison (95%) and calling out test results (88%). Nineteen participants (44.2%) also reported spending a considerable amount of time signing reports. The most prevalent areas of job satisfaction were support from laboratory directors (76.8%), autonomy (76.7%), interactions with clinicians (69.7%) and interaction with other genetics counselors (67.5%). This is the first study specifically looking at the roles of laboratory genetic counselors, which is an expanding area of genetic counseling.
On April 1, 2007, Alberta became the first province in Canada to introduce cystic fibrosis (CF) to its newborn screening program. The Alberta protocol involves a two-tier algorithm involving an immunoreactive trypsinogen measurement followed by molecular analysis using a CF panel for 39 mutations. Positive screens are followed up with sweat chloride testing and an assessment by a CF specialist. Of the 99,408 newborns screened in Alberta during the first two years of the program, 221 had a positive CF newborn screen. The program subsequently identified and initiated treatment in 31 newborns with CF. A relatively high frequency of the R117H mutation and the M1101K mutation was noted. The M1101K mutation is common in the Hutterite population. The presence of the R117H mutation has created both counselling and management dilemmas. The ability to offer CF transmembrane regulator full sequencing may help resolve diagnostic dilemmas. Counselling and management challenges are created when mutations are mild or of unknown clinical significance.