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1.
Am J Med Genet A ; 194(3): e63451, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37882230

ABSTRACT

45,X/46,XY chromosomal mosaicism presents a range of clinical manifestations, including phenotypes from Turner syndrome through genital abnormalities to apparently unaffected phenotypic males; however, the full clinical spectrum has not yet been fully delineated since prior studies on the clinical phenotype and associated risk of gonadal tumors included small cohorts and limited follow-up. To better describe the clinical manifestations and long-term outcome of patients with 45,X/46,XY mosaicism. We conducted a retrospective chart review of patients with 45,X/46,XY from three health centers (Hospital for Sick Children and Mount Sinai Hospital in Canada, and University of Pittsburgh Medical Center in United States). Of 100 patients with 45,X/46,XY karyotype, 47 were raised as females and 53 as males. Females were significantly shorter than males (p = 0.04) and height Z-score was significantly decreased with age for both genders (p = 0.02). Growth hormone (GH) treatment did not result in a significant height increase compared to the untreated group (p = 0.5). All females required puberty induction in contrast to majority of males. Five females were diagnosed with gonadal tumors, while no males were affected. Around 58% of patients exhibited at least one Turner syndrome stigmata. This study expands the clinical spectrum, long-term outcomes, and associated tumor risk in a large cohort of patients with 45,X/46,XY mosaicism. Additionally, it highlights our experience with GH therapy and prophylactic gonadectomy.


Subject(s)
Gonadal Dysgenesis, Mixed , Neoplasms , Turner Syndrome , Child , Humans , Male , Female , Mosaicism , Turner Syndrome/diagnosis , Turner Syndrome/genetics , Gonadal Dysgenesis, Mixed/genetics , Follow-Up Studies , Retrospective Studies , Phenotype
2.
PEC Innov ; 2: 100115, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37214507

ABSTRACT

Objective: To develop and evaluate a storytelling communication facilitation tool designed to help parents overcome barriers to discussing a complex multisystem genetic diagnosis with their affected children, using 22q11.2 deletion syndrome (22q11DS) as an exemplar condition. Methods: A story telling communication facilitation tool (SCFT), entitled 22q and Me, was developed for a target audience of children with 22q11DS aged 9 to 12. The SCFT was evaluated by 14 parents to assess usability and utility by comparing responses to survey questions before and after viewing the SCFT, using a Likert scale. Results: After viewing 22q and Me, parents reported that barriers to discussion were mitigated. Participants indicated they felt more comfortable and better prepared to talk to their children about 22q11DS and worried less that the diagnosis would affect their children's self-esteem. Parents described 22q and Me as engaging and able to address parental concerns. Conclusion: 22q and Me was found to be an effective tool for increasing parental comfort and ability to talk to their children about their diagnosis of 22q11DS. Innovation: This novel storytelling communication facilitation tool can serve as a model for the development of other educational tools geared at facilitating disclosure and discussion of other genetic conditions.

3.
Hum Genet ; 142(3): 321-330, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36629921

ABSTRACT

Chatbots, web-based artificial intelligence tools that simulate human conversation, are increasingly in use to support many areas of genomic medicine. However, patient preferences towards using chatbots across the range of clinical settings are unknown. We conducted a qualitative study with individuals who underwent genetic testing for themselves or their child. Participants were asked about their preferences for using a chatbot within the genetic testing journey. Thematic analysis employing interpretive description was used. We interviewed 30 participants (67% female, 50% 50 + years). Participants considered chatbots to be inefficient for very simple tasks (e.g., answering FAQs) or very complex tasks (e.g., explaining results). Chatbots were acceptable for moderately complex tasks where participants perceived a favorable return on their investment of time and energy. In addition to achieving this "sweet spot," participants anticipated that their comfort with chatbots would increase if the chatbot was used as a complement to but not a replacement for usual care. Participants wanted a "safety net" (i.e., access to a clinician) for needs not addressed by the chatbot. This study provides timely insights into patients' comfort with and perceived limitations of chatbots for genomic medicine and can inform their implementation in practice.


Subject(s)
Artificial Intelligence , Genetic Services , Child , Humans , Female , Male , Genetic Testing , Patient Preference , Software
4.
BMJ Open ; 12(4): e060899, 2022 04 29.
Article in English | MEDLINE | ID: mdl-35487723

ABSTRACT

INTRODUCTION: The high demand for genetic tests and limited supply of genetics professionals has created a need for alternative service delivery models. Digital tools are increasingly being used to support multiple points in the genetic testing journey; however, none are transferable across multiple clinical specialties and settings nor do they encompass the entire trajectory of the journey. We aim to evaluate the effectiveness of the Genetics Adviser, an interactive, patient-facing, online digital health tool that delivers pre-test counselling, provides support during the waiting period for results, and returns results with post-test counselling, encompassing the entire patient genetic testing journey. METHODS AND ANALYSIS: We will compare the Genetics Adviser paired with a brief genetic counselling session to genetic counselling alone in a randomised controlled trial. One hundred and forty patients who previously received uninformative genetic test results for their personal and family history of cancer will be recruited from familial cancer clinics in Toronto and offered all clinically significant results from genomic sequencing. Participants randomised into the intervention arm will use the Genetics Adviser to learn about genomic sequencing, receive pre-test counselling, support during the waiting period and results, supplemented with brief counselling from a genetic counsellor. Participants in the control arm will receive standard pre-test and post-test counselling for genomic sequencing from a genetic counsellor. Our primary outcome is decisional conflict following pre-test counselling from the Genetics Adviser+genetic counsellor or counsellor alone. Secondary outcomes include: knowledge, satisfaction with decision-making, anxiety, quality of life, psychological impact of results, empowerment, acceptability and economic impact for patients and the health system. A subset of patients will be interviewed to assess user experience. ETHICS AND DISSEMINATION: This study has been approved by Clinical Trials Ontario Streamlined Research Ethics Review System (REB#20-035). Results will be shared through stakeholder workshops, national and international conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04725565.


Subject(s)
Counselors , Neoplasms , Genetic Counseling/methods , Genetic Testing/methods , Humans , Quality of Life , Randomized Controlled Trials as Topic
6.
Eye (Lond) ; 36(11): 2088-2093, 2022 11.
Article in English | MEDLINE | ID: mdl-34531550

ABSTRACT

AIMS/PURPOSE: To investigate Leber congenital amaurosis (LCA) patients' expectations, decision-making processes and gene therapy-related concerns. METHODS: Using a qualitative approach, we explored perceptions of gene therapy and clinical trials among individuals with LCA. Young adults with a clinical diagnosis of LCA were recruited through the Ocular Genetics Programme at the Hospital for Sick Children. Semi-structured interviews were conducted with ten patients and analysed following the principles of qualitative description. RESULTS: Study participants were aware of ongoing gene therapy research trials and actively sought information regarding advances in ophthalmology and vision restoration. The majority of participants would enrol or were enrolled in a gene-replacement therapy trial, while a minority was ambivalent or would not enrol if provided an opportunity. Participants attributed different values to clinical trials, which influenced their willingness to participate. Intrinsic factors related to coping, adaptation to vision loss and resilience also influenced decision-making. DISCUSSION: This study highlights the complex factors involved in gene-therapy-related decision-making and acts as a proponent for adopting patient-centred care strategies when counselling individuals considering gene therapy or clinical trial participation.


Subject(s)
Leber Congenital Amaurosis , Child , Humans , Young Adult , Leber Congenital Amaurosis/genetics , Leber Congenital Amaurosis/therapy , Genetic Therapy , Vision, Ocular , Blindness/genetics , Blindness/therapy
7.
Genet Med ; 24(2): 430-438, 2022 02.
Article in English | MEDLINE | ID: mdl-34906486

ABSTRACT

PURPOSE: Demonstrating the clinical utility of genetic testing is fundamental to clinical adoption and reimbursement, but standardized definitions and measurement strategies for this construct do not exist. The Clinician-reported Genetic testing Utility InDEx (C-GUIDE) offers a novel measure to fill this gap. This study assessed its validity and inter-rater reliability. METHODS: Genetics professionals completed C-GUIDE after disclosure of test results to patients. Construct validity was assessed using regression analysis to measure associations between C-GUIDE and global item scores as well as potentially explanatory variables. Inter-rater reliability was assessed by administering a vignette-based survey to genetics professionals and calculating Krippendorff's α. RESULTS: On average, a 1-point increase in the global item score was associated with an increase of 3.0 in the C-GUIDE score (P < .001). Compared with diagnostic results, partially/potentially diagnostic and nondiagnostic results were associated with a reduction in C-GUIDE score of 9.5 (P < .001) and 10.2 (P < .001), respectively. Across 19 vignettes, Krippendorff's α was 0.68 (95% CI: 0.63-0.72). CONCLUSION: C-GUIDE showed acceptable validity and inter-rater reliability. Although further evaluation is required, C-GUIDE version 1.2 can be useful as a standardized approach to assess the clinical utility of genetic testing.


Subject(s)
Genetic Testing , Humans , Reproducibility of Results , Surveys and Questionnaires
8.
Prenat Diagn ; 41(7): 798-816, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33687072

ABSTRACT

OBJECTIVE: Describe the prevalence, perinatal and long-term outcomes of Beckwith-Wiedemann syndrome (BWS) among prenatally detected omphaloceles. METHODS: All prenatally diagnosed omphaloceles from 2010 to 2015 within a single tertiary care centre were identified. An echocardiogram and detailed fetal ultrasound were performed, and amniocentesis was offered with karyotype/microarray analysis and BWS molecular testing. Perinatal, neonatal, and long-term outcomes were retrieved for BWS cases. RESULTS: Among 92 omphaloceles, 62 had additional anomalies. Abnormal karyotypes were identified in 23/62 (37%) non-isolated and 2/30 (7%) isolated cases. One BWS case (5%) was identified among non-isolated omphaloceles and six BWS cases (37.5%) were identified among isolated omphaloceles after exclusion of aneuploidy. Among 19 BWS cases, 21% were conceived by ART. All omphaloceles underwent primary closure. Prenatally, macrosomia and polyhydramnios were seen in 42%. Macroglossia and nephromegaly were more commonly detected postnatally. Preterm birth occurred in 10/19 (53%) cases and cesarean deliveries were performed in 7/19 (40%) cases. Overall mortality was 20% (4/19). Embryonal tumors were diagnosed in 2/16 (12.5%) children, and neurodevelopmental outcomes were normal in 9/12 (75%) survivors. CONCLUSIONS: After excluding aneuploidy, BWS was identified in 37.5% and 5% of isolated and non-isolated omphaloceles, respectively. Omphaloceles were small-moderate size with good long-term surgical and neurodevelopmental outcomes when isolated.


Subject(s)
Beckwith-Wiedemann Syndrome/physiopathology , Hernia, Umbilical/physiopathology , Adult , Beckwith-Wiedemann Syndrome/complications , Beckwith-Wiedemann Syndrome/epidemiology , Correlation of Data , Female , Hernia, Umbilical/complications , Hernia, Umbilical/epidemiology , Humans , Ontario/epidemiology , Pregnancy , Prenatal Diagnosis
9.
Genet Med ; 23(6): 1086-1094, 2021 06.
Article in English | MEDLINE | ID: mdl-33654192

ABSTRACT

PURPOSE: Alternative models of genetic counseling are needed to meet the rising demand for genomic sequencing. Digital tools have been proposed as a method to augment traditional counseling and reduce burden on professionals; however, their role in delivery of genetic counseling is not established. This study explored the role of the Genomics ADvISER, a digital decision aid, in delivery of genomic counseling. METHODS: We performed secondary analysis of 52 pretest genetic counseling sessions that were conducted over the course of a randomized controlled trial evaluating the effectiveness of the Genomics ADvISER. As part of the trial, participants were randomized to receive standard counseling or use the tool and then speak with a counselor. A qualitative interpretive description approach using thematic analysis and constant comparison was used for analysis. RESULTS: In the delivery of genomic counseling, the Genomics ADvISER contributed to enhancing counseling by (1) promoting informed dialogue, (2) facilitating preference-sensitive deliberation, and (3) deepening personalization of decisions, all of which represent fundamental principles of patient-centered care: providing clear high-quality information, respecting patients' values, preferences, and expressed needs, and providing emotional support. CONCLUSION: This study demonstrates that our digital tool contributed to enhancing patient-centered care in the delivery of genomic counseling.


Subject(s)
Counselors , Genomics , Counseling , Genetic Counseling , Humans , Patient-Centered Care
10.
Genes (Basel) ; 12(2)2021 01 27.
Article in English | MEDLINE | ID: mdl-33513760

ABSTRACT

Epigenetic alterations at imprinted genes on different chromosomes have been linked to several imprinting disorders (IDs) such as Beckwith-Wiedemann syndrome (BWS) and pseudohypoparathyroidism type 1b (PHP1b). Here, we present a male patient with these two distinct IDs caused by two independent mechanisms-loss of methylation (LOM) at chromosome 11p15.5 associated with multi-locus imprinting disturbances (MLID and paternal uniparental disomy of chromosome 20 (patUPD20). A clinical diagnosis of BWS was made based on the clinical features of macrosomia, macroglossia, and umbilical hernia. The diagnosis of PHP1b was supported by the presence of reduced growth velocity and mild learning disability as well as hypocalcemia and hyperphosphatemia at 14 years of age. Molecular analyses, including genome-wide DNA methylation (Illumina 450k array), bisulfite pyrosequencing, single nucleotide polymorphism (SNP) array and microsatellite analysis, demonstrated loss of methylation (LOM) at IC2 on chromosome 11p15.5, and paternal isodisomy of the entire chromosome 20. In addition, imprinting disturbances were noted at the differentially methylated regions (DMRs) associated with DIRAS3 on chromosome 1 and PLAGL1 on chromosome 6. This is the first case report of PHP1b due to patUPD20 diagnosed in a BWS patient with LOM at IC2 demonstrating etiologic heterogeneity for multiple imprinting disorders in a single individual.


Subject(s)
Beckwith-Wiedemann Syndrome/diagnosis , Beckwith-Wiedemann Syndrome/genetics , Chromosomes, Human, Pair 20 , Genetic Association Studies , Genetic Predisposition to Disease , Paternal Inheritance , Uniparental Disomy , Child , CpG Islands , DNA Methylation , Epigenesis, Genetic , Gene Expression Profiling , Genomic Imprinting , Humans , Loss of Heterozygosity , Male , Microsatellite Repeats , Pedigree , Polymorphism, Single Nucleotide
11.
Br J Cancer ; 124(2): 437-446, 2021 01.
Article in English | MEDLINE | ID: mdl-33012783

ABSTRACT

BACKGROUND: Although cure rates for Wilms tumours (WT) are high, many patients receive therapy with attendant long-term complications. Our goal was to stratify WT using genome-wide analyses to identify candidate molecular features for patients who would benefit from a reduction in therapy. METHODS: We generated DNA methylation and exome sequencing data on WT-kidney pairs (n = 57) and unpaired tumours (n = 27) collected either at our centre or by the Children's Oncology Group. Samples were divided into a discovery set (n = 32) and validation set (n = 52). RESULTS: Analysis of DNA methylation revealed two subgroups of WT with distinct features. Subgroup A has a similar DNA methylation profile to mature kidney, while Subgroup B has genome-wide dysregulation of DNA methylation. The rate of non-synonymous missense mutations and segmental chromosomal aberrations was higher in Subgroup B tumours, suggesting that this group has genome instability related to its epigenetic state. Subgroup A had a higher proportion of cases of bilateral disease. Tumours with high-risk histology or from patients who relapsed were only found in Subgroup B. CONCLUSION: We have identified subgroup-specific molecular events that could inform future work supporting more targeted therapeutic approaches and patient stratification. We propose a novel developmental tumour model based on these findings.


Subject(s)
Kidney Neoplasms/genetics , Wilms Tumor/genetics , Child , Chromosome Aberrations , DNA Methylation/genetics , Female , Gene Expression Profiling/methods , Genes, Wilms Tumor , Humans , Kidney Neoplasms/classification , Male , Mutation , Exome Sequencing , Wilms Tumor/classification
12.
J Genet Couns ; 28(5): 982-992, 2019 10.
Article in English | MEDLINE | ID: mdl-31313416

ABSTRACT

Consanguinity, the union between two individuals who are related as second cousins or closer, is a long-standing and respected tradition in many communities. Although there are social and economic benefits of consanguineous unions, offspring are at increased risk of having an inherited genetic condition or congenital anomaly. Genetic counseling services for consanguinity are available to couples at many centers. However, little is known about patient expectations of and experiences with genetic counseling for this indication, or their perspectives on genetic screening relevant to family planning, such as expanded carrier screening (ECS). This exploratory qualitative study involved interviews with 13 individuals who had recently received preconception or prenatal genetic counseling for consanguinity at a single center. We sought to gain insight into their expectations for the genetic counseling session, experiences discussing family history and reproductive risks with the genetic counselor, and views on ECS. Interview transcripts were analyzed using an interpretive descriptive approach. Data analysis revealed three main themes: (a) anticipation balances apprehension before the appointment; (b) genetic counseling reduces anxiety and empowers; and (c) the need for wider information dissemination about consanguinity-related risks and genetic services. Our findings support the personal utility of genetic counseling for consanguinity and demonstrate the need for increased visibility and access to genetics information, counseling, and testing relevant to this patient population.


Subject(s)
Consanguinity , Family , Genetic Counseling/methods , Anxiety , Appointments and Schedules , Counseling , Counselors , Family Planning Services , Female , Genetic Services , Genetic Testing , Humans , Male , Mass Screening , Medical History Taking , Motivation , Pregnancy , Risk , Sex Education
13.
Pharmacogenomics ; 20(5): 319-329, 2019 04.
Article in English | MEDLINE | ID: mdl-30983503

ABSTRACT

Pharmacogenomic (PGx) tests represent significant advances in precision medicine. Our aim was to explore perceptions following the return of PGx results, medication management, and disclosure to providers. We surveyed clients who had PGx testing and conducted a chart review of PGx results. Respectively, 84% and 94% of participants found pre- and post-test genetic counseling helpful. There was a significant difference in disclosure, while 6% disclosed results to a pharmacist, 50% disclosed to a physician. Qualitative analysis identified three themes: 1) psychological response; 2) perceived utility; 3) experiences with disclosure. Our study supports the provision of genetic counseling for a non-disease related genetic test. Benefits of PGx testing can be optimized by the collaboration of physicians, pharmacists, genetic counselors and patients.


Subject(s)
Pharmacogenomic Testing , Precision Medicine , Adolescent , Adult , Aged , Cohort Studies , Disclosure , Female , Genetic Counseling/psychology , Health Expenditures , Humans , Male , Middle Aged , Patient Care Management , Patient Participation/psychology , Patient Satisfaction , Perception , Pharmacogenomic Testing/economics , Precision Medicine/psychology , Surveys and Questionnaires , Young Adult
14.
Pediatr Blood Cancer ; 66(1): e27445, 2019 01.
Article in English | MEDLINE | ID: mdl-30207072

ABSTRACT

BACKGROUND: Hereditary tumor predisposition syndromes (HTPSs) are being recognized more frequently in the etiology of pediatric cancer. Previous research indicates that disclosure of tumor susceptibility is a significant event in adolescents' lives. Insight into adolescents' adjustment to knowledge of their syndromes can guide healthcare delivery, particularly genetic counseling. This study explored the experiences of adolescents with hereditary tumor predisposition and their perceptions of living at risk. METHODS: Seven adolescents, ages 14 to 17, representing six different childhood-onset HTPSs, were purposively sampled and interviewed using a study-specific semistructured interview guide. We explored the disclosure process, support systems, and the perceived benefits and harms of knowledge of hereditary tumor susceptibility. Interview transcripts were analyzed via interpretive description. RESULTS: Three major themes emerged from the data: (1) The benefits of knowledge outweigh the harms; (2) context surrounding genetic testing must be recognized; and (3) self-concept is influenced but not defined by tumor risk. CONCLUSIONS: We conclude that adolescents recognize the challenges associated with awareness of tumor predisposition but may also identify positive aspects in their experiences, reflecting a changed life perspective. Results of this exploratory study suggest strategies that can guide pretest and posttest genetic counseling of adolescents for HTPSs, facilitating the adaptive incorporation of genetic information into an adolescent's self-concept.


Subject(s)
Genetic Counseling , Genetic Predisposition to Disease , Neoplastic Syndromes, Hereditary/genetics , Neoplastic Syndromes, Hereditary/psychology , Adolescent , Female , Follow-Up Studies , Genetic Testing , Humans , Male , Qualitative Research , Surveys and Questionnaires
15.
J Genet Couns ; 27(5): 1130-1147, 2018 09.
Article in English | MEDLINE | ID: mdl-29516345

ABSTRACT

The introduction of chromosomal microarray (CMA) into the prenatal setting has involved considerable deliberation due to the wide range of possible outcomes (e.g., copy number variants of uncertain clinical significance). Such issues are typically discussed in pre-test counseling for pregnant women to support informed decision-making regarding prenatal testing options. This research study aimed to assess the level of informed decision-making with respect to prenatal CMA and the factor(s) influencing decision-making to accept CMA for the selected prenatal testing procedure (i.e., chorionic villus sampling or amniocentesis). We employed a questionnaire that was adapted from a three-dimensional measure previously used to assess informed decision-making with respect to prenatal screening for Down syndrome and neural tube defects. This measure classifies an informed decision as one that is knowledgeable, value-consistent, and deliberated. Our questionnaire also included an optional open-ended question, soliciting factors that may have influenced the participants' decision to accept prenatal CMA; these responses were analyzed qualitatively. Data analysis on 106 participants indicated that 49% made an informed decision (i.e., meeting all three criteria of knowledgeable, deliberated, and value-consistent). Analysis of 59 responses to the open-ended question showed that "the more information the better" emerged as the dominant factor influencing both informed and uninformed participants' decisions to accept prenatal CMA. Despite learning about the key issues in pre-test genetic counseling, our study classified a significant portion of women as making uninformed decisions due to insufficient knowledge, lack of deliberation, value-inconsistency, or a combination of these three measures. Future efforts should focus on developing educational approaches and counseling strategies to effectively increase the rate of informed decision-making among women offered prenatal CMA.


Subject(s)
Chromosome Aberrations , Decision Making , Prenatal Diagnosis/psychology , Adolescent , Adult , Amniocentesis , Down Syndrome/genetics , Female , Genetic Counseling/psychology , Genetic Testing/methods , Humans , Neural Tube Defects/genetics , Pregnancy
17.
Eur J Hum Genet ; 26(5): 740-744, 2018 05.
Article in English | MEDLINE | ID: mdl-29453418

ABSTRACT

Whole-genome sequencing (WGS) as a first-tier diagnostic test could transform medical genetic assessments, but there are limited data regarding its clinical use. We previously showed that WGS could feasibly be deployed as a single molecular test capable of a higher diagnostic rate than current practices, in a prospectively recruited cohort of 100 children meeting criteria for chromosomal microarray analysis. In this study, we report on the added diagnostic yield with re-annotation and reanalysis of these WGS data ~2 years later. Explanatory variants have been discovered in seven (10.9%) of 64 previously undiagnosed cases, in emerging disease genes like HMGA2. No new genetic diagnoses were made by any other method in the interval period as part of ongoing clinical care. The results increase the cumulative diagnostic yield of WGS in the study cohort to 41%. This represents a greater than 5-fold increase over the chromosomal microarrays, and a greater than 3-fold increase over all the clinical genetic testing ordered in practice. These findings highlight periodic reanalysis as yet another advantage of genomic sequencing in heterogeneous disorders. We recommend reanalysis of an individual's genome-wide sequencing data every 1-2 years until diagnosis, or sooner if their phenotype evolves.


Subject(s)
Genetic Diseases, Inborn/genetics , Genetic Predisposition to Disease , Genetic Testing/methods , Whole Genome Sequencing/methods , Female , Follow-Up Studies , Genetic Diseases, Inborn/diagnosis , Genetic Diseases, Inborn/physiopathology , Genome, Human/genetics , Humans , Male , Microarray Analysis , Pathology, Molecular , Sequence Analysis, DNA
18.
CMAJ ; 190(5): E126-E136, 2018 02 05.
Article in English | MEDLINE | ID: mdl-29431110

ABSTRACT

BACKGROUND: The Personal Genome Project Canada is a comprehensive public data resource that integrates whole genome sequencing data and health information. We describe genomic variation identified in the initial recruitment cohort of 56 volunteers. METHODS: Volunteers were screened for eligibility and provided informed consent for open data sharing. Using blood DNA, we performed whole genome sequencing and identified all possible classes of DNA variants. A genetic counsellor explained the implication of the results to each participant. RESULTS: Whole genome sequencing of the first 56 participants identified 207 662 805 sequence variants and 27 494 copy number variations. We analyzed a prioritized disease-associated data set (n = 1606 variants) according to standardized guidelines, and interpreted 19 variants in 14 participants (25%) as having obvious health implications. Six of these variants (e.g., in BRCA1 or mosaic loss of an X chromosome) were pathogenic or likely pathogenic. Seven were risk factors for cancer, cardiovascular or neurobehavioural conditions. Four other variants - associated with cancer, cardiac or neurodegenerative phenotypes - remained of uncertain significance because of discrepancies among databases. We also identified a large structural chromosome aberration and a likely pathogenic mitochondrial variant. There were 172 recessive disease alleles (e.g., 5 individuals carried mutations for cystic fibrosis). Pharmacogenomics analyses revealed another 3.9 potentially relevant genotypes per individual. INTERPRETATION: Our analyses identified a spectrum of genetic variants with potential health impact in 25% of participants. When also considering recessive alleles and variants with potential pharmacologic relevance, all 56 participants had medically relevant findings. Although access is mostly limited to research, whole genome sequencing can provide specific and novel information with the potential of major impact for health care.


Subject(s)
Genetic Variation/genetics , Genome, Human/genetics , Sequence Analysis, DNA/methods , Whole Genome Sequencing/methods , Canada , Female , Genes, Recessive/genetics , Genetic Predisposition to Disease/genetics , Humans , Male
19.
Genet Med ; 20(4): 435-443, 2018 04.
Article in English | MEDLINE | ID: mdl-28771251

ABSTRACT

PurposeGenetic testing is an integral diagnostic component of pediatric medicine. Standard of care is often a time-consuming stepwise approach involving chromosomal microarray analysis and targeted gene sequencing panels, which can be costly and inconclusive. Whole-genome sequencing (WGS) provides a comprehensive testing platform that has the potential to streamline genetic assessments, but there are limited comparative data to guide its clinical use.MethodsWe prospectively recruited 103 patients from pediatric non-genetic subspecialty clinics, each with a clinical phenotype suggestive of an underlying genetic disorder, and compared the diagnostic yield and coverage of WGS with those of conventional genetic testing.ResultsWGS identified diagnostic variants in 41% of individuals, representing a significant increase over conventional testing results (24%; P = 0.01). Genes clinically sequenced in the cohort (n = 1,226) were well covered by WGS, with a median exonic coverage of 40 × ±8 × (mean ±SD). All the molecular diagnoses made by conventional methods were captured by WGS. The 18 new diagnoses made with WGS included structural and non-exonic sequence variants not detectable with whole-exome sequencing, and confirmed recent disease associations with the genes PIGG, RNU4ATAC, TRIO, and UNC13A.ConclusionWGS as a primary clinical test provided a higher diagnostic yield than conventional genetic testing in a clinically heterogeneous cohort.


Subject(s)
Genetic Association Studies , Genetic Diseases, Inborn/diagnosis , Genetic Diseases, Inborn/genetics , Genetic Predisposition to Disease , Genetic Testing , Sequence Analysis, DNA , Whole Genome Sequencing , Computational Biology/methods , DNA Copy Number Variations , Exome , Female , Genetic Association Studies/methods , Genetic Association Studies/standards , Genetic Testing/methods , Genetic Testing/standards , Genetic Variation , Humans , Male , Molecular Sequence Annotation , Phenotype , Sequence Analysis, DNA/methods , Sequence Analysis, DNA/standards , Exome Sequencing/methods , Exome Sequencing/standards , Whole Genome Sequencing/methods , Whole Genome Sequencing/standards
20.
Eur J Hum Genet ; 25(12): 1303-1312, 2017 12.
Article in English | MEDLINE | ID: mdl-29158552

ABSTRACT

The clinical use of whole-genome sequencing (WGS) is expected to alter pediatric medical management. The study aimed to describe the type and cost of healthcare activities following pediatric WGS compared to chromosome microarray (CMA). Healthcare activities prompted by WGS and CMA were ascertained for 101 children with developmental delay over 1 year. Activities following receipt of non-diagnostic CMA were compared to WGS diagnostic and non-diagnostic results. Activities were costed in 2016 Canadian dollars (CDN). Ongoing care accounted for 88.6% of post-test activities. The mean number of lab tests was greater following CMA than WGS (0.55 vs. 0.09; p = 0.007). The mean number of specialist visits was greater following WGS than CMA (0.41 vs. 0; p = 0.016). WGS results (diagnostic vs. non-diagnostic) modified the effect of test type on mean number of activities (p < 0.001). The cost of activities prompted by diagnostic WGS exceeded $557CDN for 10% of cases. In complex pediatric care, CMA prompted additional diagnostic investigations while WGS prompted tailored care guided by genotypic variants. Costs for prompted activities were low for the majority and constitute a small proportion of total test costs. Optimal use of WGS depends on robust evaluation of downstream care and cost consequences.


Subject(s)
Costs and Cost Analysis , Genetic Testing/economics , Whole Genome Sequencing/economics , Canada , Child , Genetic Testing/methods , Humans , Oligonucleotide Array Sequence Analysis/economics , Oligonucleotide Array Sequence Analysis/methods , Whole Genome Sequencing/methods
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