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PURPOSE: Neurofibromatosis type 2 (NF2) and schwannomatosis (SWN) are genetically distinct tumor predisposition syndromes with overlapping phenotypes. We sought to update the diagnostic criteria for NF2 and SWN by incorporating recent advances in genetics, ophthalmology, neuropathology, and neuroimaging. METHODS: We used a multistep process, beginning with a Delphi method involving global disease experts and subsequently involving non-neurofibromatosis clinical experts, patients, and foundations/patient advocacy groups. RESULTS: We reached consensus on the minimal clinical and genetic criteria for diagnosing NF2 and SWN. These criteria incorporate mosaic forms of these conditions. In addition, we recommend updated nomenclature for these disorders to emphasize their phenotypic overlap and to minimize misdiagnosis with neurofibromatosis type 1. CONCLUSION: The updated criteria for NF2 and SWN incorporate clinical features and genetic testing, with a focus on using molecular data to differentiate the 2 conditions. It is likely that continued refinement of these new criteria will be necessary as investigators study the diagnostic properties of the revised criteria and identify new genes associated with SWN. In the revised nomenclature, the term "neurofibromatosis 2" has been retired to improve diagnostic specificity. ispartof: GENETICS IN MEDICINE vol:24 issue:9 pages:1967-1977 ispartof: location:United States status: published

Ongoing rapid growth in the need for genetic services has the potential to severely strain the capacity of the clinical genetics workforce to deliver this care. Unfortunately, assessments of the scale of this health policy challenge and potential solutions are hampered by the lack of a consolidated evidence base on the growth in genetic service utilization. To enable health policy research and strategic planning by health systems in this area, we conducted a scoping review of the literature on the utilization and uptake of clinical genetics services in high-income countries published between 2010 and 2018. One-hundred-and-ninety-five unique studies were included in the review. Most focused on cancer (85/195; 44%) and prenatal care (50/195; 26%), which are consistently the two areas with the greatest volume of genetic service utilization in both the United States and other high-income countries. Utilization and uptake rates varied considerably and were influenced by contextual factors including health system characteristics, provider knowledge, and patient preferences. Moreover, growth in genetic service utilization appears to be driven to a significant degree by technological advances and the integration of new tests into clinical care. Our review highlights both the policy challenge posed by the rapid growth in the utilization of genetic services and the variability in this trend across clinical indications and health systems.

People with pre-existing conditions may be more susceptible to severe COVID-19 when infected by SARS-CoV-2. The relative risk and severity of SARS-CoV-2 infection in people with rare diseases such as neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), or schwannomatosis (SWN) is unknown.We investigated the proportions of people with NF1, NF2, or SWN in the National COVID Cohort Collaborative (N3C) electronic health record data set who had a positive test result for SARS-CoV-2 or COVID-19.The cohort sizes in N3C were 2501 (NF1), 665 (NF2), and 762 (SWN). We compared these with N3C cohorts of patients with other rare diseases (98-9844 individuals) and the general non-NF population of 5.6 million. The site- and age-adjusted proportion of people with NF1, NF2, or SWN who had a positive test result for SARS-CoV-2 or COVID-19 (collectively termed positive cases) was not significantly higher than in individuals without NF or other selected rare diseases. There were no severe outcomes reported in the NF2 or SWN cohorts. The proportion of patients experiencing severe outcomes was no greater for people with NF1 than in cohorts with other rare diseases or the general population.Having NF1, NF2, or SWN does not appear to increase the risk of being SARS-CoV-2 positive or of being a patient with COVID-19 or of developing severe complications from SARS-CoV-2.

This study describes the cost trajectory of the standard diagnostic care pathway for children with suspected genetic disorders in British Columbia, Canada. Average annual per-patient costs were estimated using medical records review and a caregiver survey for a cohort of 498 children referred to BC Children’s and Women’s Hospitals (CW exome and genome sequencing) to 500 families of children with suspected genetic disorders. Direct costs peaked in the first year of patients’ diagnostic odyssey, with an average of C$2257 per patient (95% confidence interval [CI] C$2074, C$2441) for diagnostic testing and C$631 (95% CI C$543, C$727) for specialist consultations at C&W. In subsequent years, direct costs accrued at a constant rate, with an estimated annual per-patient cost of C$511 (95% CI C$473, C$551) for diagnostic testing and C$334 (95% CI C$295, C$369) for consultations at C&W. Travel costs and caregiver productivity loss associated with attending diagnosis-related physician appointments averaged C$1907/family/year. The continuing long-term accrual of costs by undiagnosed patients suggests that economic evaluations of diagnostic GWS services should use longer time horizons than have typically been used.

BackgroundRegenerating islet-derived protein 3α (REG3α) is an antimicrobial peptide secreted by intestinal Paneth cells. Circulating REG3α has been identified as a gut damage marker in inflammatory bowel diseases. People living with human immunodeficiency virus (PWH) on antiretroviral therapy (ART) present with an abnormal intestinal landscape leading to microbial translocation, persistent inflammation, and development of non-AIDS comorbidities. Herein, we assessed REG3α as a marker of gut damage in PWH.MethodsPlasma from 169 adult PWH, including 30 elite controllers (ECs), and 30 human immunodeficiency virus (HIV)–uninfected controls were assessed. REG3α plasma levels were compared with HIV disease progression, epithelial gut damage, microbial translocation, and immune activation markers.ResultsCross-sectionally, REG3α levels were elevated in untreated and ART-treated PWH compared with controls. ECs also had elevated REG3α levels compared to controls. Longitudinally, REG3α levels increased in PWH without ART and decreased in those who initiated ART. REG3α levels were inversely associated with CD4 T-cell count and CD4:CD8 ratio, while positively correlated with HIV viral load in untreated participants, and with fungal product translocation and inflammatory markers in all PWH.ConclusionsPlasma REG3α levels were elevated in PWH, including ECs. The gut inflammatory marker REG3α may be used to evaluate therapeutic interventions and predict non-AIDS comorbidity risks in PWH.

Purpose To examine the prevalence of, and factors associated with, atypical antipsychotic use among U.S. pregnant women, and potential associations between early pregnancy atypical antipsychotic use and risk for 14 birth defects. Methods We analyzed data from the National Birth Defects Prevention Study (1997–2011), a U.S. population-based case-control study examining risk factors for major structural birth defects. Results Atypical antipsychotic use during pregnancy was more common among women with pre-pregnancy obesity, and women who reported illicit drug use before and during pregnancy, smoking during pregnancy, alcohol use during pregnancy, or use of other psychiatric medications during pregnancy. We observed elevated associations (defined as a crude odds ratio [cOR] ≥2.0) between early pregnancy atypical antipsychotic use and conotruncal heart defects (6 exposed cases; cOR: 2.3, 95% confidence interval [CI]: 0.9–6.1), and more specifically Tetralogy of Fallot (3 exposed cases; cOR: 2.5, 95% CI: 0.7–8.8), cleft palate (4 exposed cases, cOR: 2.5, 95% CI: 0.8–7.6), anorectal atresia/stenosis (3 exposed cases, cOR: 2.8, 95% CI: 0.8–9.9), and gastroschisis (3 exposed cases, cOR: 2.1, 95% CI: 0.6–7.3). Conclusions Our findings support the close clinical monitoring of pregnant women using atypical antipsychotics. Women treated with atypical antipsychotics generally access healthcare services before pregnancy; efforts to reduce correlates of atypical antipsychotic use might improve maternal and infant health in this population.

This study aimed to compare downstream utilization of medical services among critically ill infants admitted to intensive care units who received rapid exome sequencing (ES) and those who followed alternative diagnostic testing pathways.Using propensity score-weighted regression models including sex, age at admission, and severity indicators, we compared a group of 47 infants who underwent rapid ES with a group of 211 infants who did not receive rapid ES. Utilization and cost indicators were compared between cohorts using negative binomial models for utilization and two-part models for costs.After controlling for patients' sociodemographic and clinical characteristics, we found no statistically significant difference in outpatient visits, hospitalizations, intensive care unit or total length of stay, or length of stay-associated costs between the cohorts at 12- or 26-month follow-up. Similarly, there was no evidence of higher utilization or costs by the ES group when infants who died were removed from the analysis.When examining utilization during and beyond the diagnostic trajectory, there is no evidence that ES changes frequency of outpatient visits or use of in-hospital resources in critically ill infants with suspected genetic disorders.

Background Neurofibromatosis 1 (NF1) is a rare autosomal dominant disease characterized by increased Schwann cell proliferation in peripheral nerves. Several small studies of brain morphology in children with NF1 have found increased total brain volume, total white matter volume and/or corpus callosum area. Some studies (mostly in children with NF1) also attempted to correlate changes in brain morphology and volume with cognitive or behavioural abnormalities, although the findings were inconsistent. We aimed to characterize alterations in brain volumes by three-dimensional (3D) MRI in adults with NF1 in major intracranial sub-regions. We also aimed to assess the effect of age on these volumes and correlated brain white matter and grey matter volumes with neuropsychometric findings in adults with NF1. Methods We obtained brain volume measurements using 3D magnetic resonance imaging for 351 adults with NF1 and, as a comparison group, 43 adults with neurofibromatosis 2 (NF2) or Schwannomatosis. We assessed a subset of 19 adults with NF1 for clinical severity of NF1 features and neurological problems and conducted psychometric testing for attention deficiencies and intelligence quotient. We compared brain volumes between NF1 patients and controls and correlated volumetric measurements to clinical and psychometric features in the NF1 patients. Results Total brain volume and total and regional white matter volumes were all significantly increased in adults with NF1. Grey matter volume decreased faster with age in adults with NF1 than in controls. Greater total brain volume and white matter volume were correlated with lower attention deficits and higher intelligence quotients in adults with NF1. Conclusion Our findings are consistent with the hypothesis that dysregulation of brain myelin production is a cardinal manifestation of NF1 and that these white matter changes may be functionally important in affected adults.

Detection of short tandem repeat (STR) expansions with standard short-read sequencing is challenging due to the difficulty in mapping multicopy repeat sequences. In this study, we explored how the long-range sequence information of barcode linked-read sequencing (BLRS) can be leveraged to improve repeat-read detection. We also devised a novel algorithm using BLRS barcodes for distance estimation and evaluated its application for STR genotyping. Both approaches were designed for genotyping large expansions (> 1 kb) that cannot be sized accurately by existing methods. Using simulated and experimental data of genomes with STR expansions from multiple BLRS platforms, we validated the utility of barcode and phasing information in attaining better STR genotypes compared to standard short-read sequencing. Although the coverage bias of extremely GC-rich STRs is an important limitation of BLRS, BLRS is an effective strategy for genotyping many other STR loci.

BackgroundExpansions of short tandem repeats are the cause of many neurogenetic disorders including familial amyotrophic lateral sclerosis, Huntington disease, and many others. Multiple methods have been recently developed that can identify repeat expansions in whole genome or exome sequencing data. Despite the widely-recognized need for visual assessment of variant calls in clinical settings, current computational tools lack the ability to produce such visualizations for repeat expansions. Expanded repeats are difficult to visualize because they correspond to large insertions relative to the reference genome and involve many misaligning and ambiguously aligning reads.ResultsWe implemented REViewer, a computational method for visualization of sequencing data in genomic regions containing long repeat expansions. To generate a read pileup, REViewer reconstructs local haplotype sequences and distributes reads to these haplotypes in a way that is most consistent with the fragment lengths and evenness of read coverage. To create appropriate training materials for onboarding new users, we performed a concordance study involving 12 scientists involved in STR research. We used the results of this study to create a user guide that describes the basic principles of using REViewer as well as a guide to the typical features of read pileups that correspond to low confidence repeat genotype calls. Additionally, we demonstrated that REViewer can be used to annotate clinically-relevant repeat interruptions by comparing visual assessment results of 44 FMR1 repeat alleles with the results of triplet repeat primed PCR. For 38 of these alleles, the results of visual assessment were consistent with triplet repeat primed PCR.ConclusionsRead pileup plots generated by REViewer offer an intuitive way to visualize sequencing data in regions containing long repeat expansions. Laboratories can use REViewer to assess the quality of repeat genotype calls as well as to visually detect interruptions or other imperfections in the repeat sequence and the surrounding flanking regions.

Background Expansions of short tandem repeats are the cause of many neurogenetic disorders including familial amyotrophic lateral sclerosis, Huntington disease, and many others. Multiple methods have been recently developed that can identify repeat expansions in whole genome or exome sequencing data. Despite the widely recognized need for visual assessment of variant calls in clinical settings, current computational tools lack the ability to produce such visualizations for repeat expansions. Expanded repeats are difficult to visualize because they correspond to large insertions relative to the reference genome and involve many misaligning and ambiguously aligning reads. Results We implemented REViewer, a computational method for visualization of sequencing data in genomic regions containing long repeat expansions and FlipBook, a companion image viewer designed for manual curation of large collections of REViewer images. To generate a read pileup, REViewer reconstructs local haplotype sequences and distributes reads to these haplotypes in a way that is most consistent with the fragment lengths and evenness of read coverage. To create appropriate training materials for onboarding new users, we performed a concordance study involving 12 scientists involved in short tandem repeat research. We used the results of this study to create a user guide that describes the basic principles of using REViewer as well as a guide to the typical features of read pileups that correspond to low confidence repeat genotype calls. Additionally, we demonstrated that REViewer can be used to annotate clinically relevant repeat interruptions by comparing visual assessment results of 44 FMR1 repeat alleles with the results of triplet repeat primed PCR. For 38 of these alleles, the results of visual assessment were consistent with triplet repeat primed PCR. Conclusions Read pileup plots generated by REViewer offer an intuitive way to visualize sequencing data in regions containing long repeat expansions. Laboratories can use REViewer and FlipBook to assess the quality of repeat genotype calls as well as to visually detect interruptions or other imperfections in the repeat sequence and the surrounding flanking regions. REViewer and FlipBook are available under open-source licenses at https://github.com/illumina/REViewer and https://github.com/broadinstitute/flipbook respectively.

Monoamine neurotransmitter disorders present predominantly with neurologic features, including dystonic or dyskinetic cerebral palsy and movement disorders. Genetic conditions that lead to secondary defects in the synthesis, catabolism, transport, and metabolism of biogenic amines can lead to neurotransmitter abnormalities, which can present with similar features. Eleven patients with secondary neurotransmitter abnormalities were enrolled between 2011 and 2015. All patients underwent research-based whole exome and/or whole genome sequencing (WES/WGS). A trial of treatment with levodopa/carbidopa and 5-hydroxytryptophan was initiated. In six families with abnormal neurotransmitter profiles and neurological phenotypes, variants in known disease-causing genes (KCNJ6, SCN2A, CSTB in 2 siblings, NRNX1, KIF1A and PAK3) were identified, while one patient had a variant of uncertain significance in a candidate gene (DLG4) that may explain her phenotype. In 3 patients, no compelling candidate genes were identified. A trial of neurotransmitter replacement therapy led to improvement in motor and behavioral symptoms in all but two patients. The patient with KCNJ6 variant did not respond to L-dopa therapy, but rather experienced increased dyskinetic movements even at low dose of medication. The patient’s symptoms harboring the NRNX1 deletion remained unaltered. This study demonstrates the utility of genome-wide sequencing in further understanding the etiology and pathophysiology of neurometabolic conditions, and the potential of secondary neurotransmitter deficiencies to serve as novel therapeutic targets. As there was a largely favorable response to therapy in our case series, a careful trial of neurotransmitter replacement therapy should be considered in patients with cerebrospinal fluid (CSF) monoamines below reference range.

Genome-wide sequencing (GWS) is a standard of care for diagnosis of suspected genetic disorders, but the proportion of patients found to have pathogenic or likely pathogenic variants ranges from less than 30% to more than 60% in reported studies. It has been suggested that the diagnostic rate can be improved by interpreting genomic variants in the context of each affected individual's full clinical picture and by regular follow-up and reinterpretation of GWS laboratory results. Trio exome sequencing was performed in 415 families and trio genome sequencing in 85 families in the CAUSES study. The variants observed were interpreted by a multidisciplinary team including laboratory geneticists, bioinformaticians, clinical geneticists, genetic counselors, pediatric subspecialists, and the referring physician, and independently by a clinical laboratory using standard American College of Medical Genetics and Genomics (ACMG) criteria. Individuals were followed for an average of 5.1 years after testing, with clinical reassessment and reinterpretation of the GWS results as necessary. The multidisciplinary team established a diagnosis of genetic disease in 43.0% of the families at the time of initial GWS interpretation, and longitudinal follow-up and reinterpretation of GWS results produced new diagnoses in 17.2% of families whose initial GWS interpretation was uninformative or uncertain. Reinterpretation also resulted in rescinding a diagnosis in four families (1.9%). Of the families studied, 33.6% had ACMG pathogenic or likely pathogenic variants related to the clinical indication. Close collaboration among clinical geneticists, genetic counselors, laboratory geneticists, bioinformaticians, and individuals’ primary physicians, with ongoing follow-up, reanalysis, and reinterpretation over time, can improve the clinical value of GWS.

PURPOSE: By incorporating major developments in genetics, ophthalmology, dermatology, and neuroimaging, to revise the diagnostic criteria for neurofibromatosis type 1 (NF1) and to establish diagnostic criteria for Legius syndrome (LGSS). METHODS: We used a multistep process, beginning with a Delphi method involving global experts and subsequently involving non-NF experts, patients, and foundations/patient advocacy groups. RESULTS: We reached consensus on the minimal clinical and genetic criteria for diagnosing and differentiating NF1 and LGSS, which have phenotypic overlap in young patients with pigmentary findings. Criteria for the mosaic forms of these conditions are also recommended. CONCLUSION: The revised criteria for NF1 incorporate new clinical features and genetic testing, whereas the criteria for LGSS were created to differentiate the two conditions. It is likely that continued refinement of these new criteria will be necessary as investigators (1) study the diagnostic properties of the revised criteria, (2) reconsider criteria not included in this process, and (3) identify new clinical and other features of these conditions. For this reason, we propose an initiative to update periodically the diagnostic criteria for NF1 and LGSS. ispartof: GENETICS IN MEDICINE vol:23 issue:8 pages:1506-1513 ispartof: location:United States status: published

Objective Neurofibromatosis 1 (NF1) is a rare autosomal dominant disease that causes the dysregulated growth of Schwann cells. Most reported studies of brain morphology in NF1 patients have included only children, and clinical implications of the observed changes later in life remain unclear. In this study, we used MRI to characterize brain morphology in adults with NF1. Methods Planar (2D) MRI measurements of 29 intracranial structures were compared in 389 adults with NF1 and 112 age- and sex-matched unaffected control subjects. The 2D measurements were correlated with volumetric (3D) brain measurements in 99 of the adults with NF1 to help interpret the 2D findings. A subset (n = 70) of these NF1 patients also received psychometric testing for attention deficits and IQ and was assessed for clinical severity of NF1 features and neurological problems. Correlation analysis was performed between the MRI measurements and clinical and psychometric features of these patients. Results Four of nine corpus callosum measurements were significantly greater in adults with NF1 than in sex- and age-matched controls. All seven brainstem measurements were significantly greater in adults with NF1 than in controls. Increased corpus callosum and brainstem 2D morphology were correlated with increased total white matter volume among the NF1 patients. No robust correlations were observed between the 2D size of these structures and clinical or neuropsychometric assessments. Conclusion Our findings are consistent with the hypothesis that dysregulation of brain myelin production is an important manifestation of NF1 in adults.

Objective: Examine the relationship between prescription opioid analgesic use during pregnancy and preterm birth or term low birthweight.Design, setting, and participants: We analyzed data from the National Birth Defects Prevention Study, a US multisite, population-based study, for births from 1997 to 2011. We defined exposure as self-reported prescription opioid use between one month before conception and the end of pregnancy, and we dichotomized opioid use duration by ≤7 days and >7 days.Main outcome measures: We examined the association between opioid use and preterm birth (defined as gestational age 7 days; codeine (170, 36 percent) and hydrocodone (163, 35 percent) were the most commonly reported opioids. Opioid use was associated with slightly increased risk for preterm birth [adjusted odds ratio, 1.4; 95 percent confidence interval, 1.0, 1.9], particularly with hydrocodone [1.6; 1.0, 2.6], meperidine [2.5; 1.2, 5.2], or morphine [3.0; 1.5, 6.1] use for any duration; however, opioid use was not significantly associated with term low birthweight.Conclusions: Preterm birth occurred more frequently among infants of women reporting prescription opioid use during pregnancy. However, we could not determine if these risks relate to the drug or to indications for use. Patients who use opioids during pregnancy should be counseled by their practitioners about this and other potential risks associated with opioid use in pregnancy.

Genomic testing is becoming routine for diagnosing rare childhood genetic disease. Evidence underlying sustainable implementation is limited, focusing on short-term endpoints such as diagnostic yield, unable to fully characterize patient and family valued outcomes. Although genomic testing is becoming widely available, evidentiary and outcomes uncertainty persist as key challenges for implementation. We examine whether the current evidence base reflects public tolerance for uncertainty for genomics to diagnose rare childhood genetic disease. We conducted focus groups with general population parents in Vancouver, Canada, and Oxford, United Kingdom, to discuss expectations and concerns related to genomic testing to diagnose rare childhood genetic disease. Applying a purposive sampling technique, recruitment continued until thematic saturation was reached. Transcripts were analysed using thematic analysis. Thirty-three parents participated across four focus groups. Participants valued causal diagnoses alongside management strategies to improve patient health and wellbeing. Further, participants valued expanding the evidence base to reduce evidentiary uncertainty while ensuring security of information. Willingness to pay out of pocket for testing reflected perceived familial health benefit. Diagnostic yield fails to fully capture valued outcomes, and efforts to resolve uncertainty better reflect public priorities. Evaluations of genomic testing that fully integrate valued endpoints are necessary to ensure consistency with best practices and public willingness to accept the uncertain familial benefit.

Purpose Intellectual disability (ID) results from a heterogeneous group of disorders and affects 1% to 2% of children. ID frequently occurs in association with other clinical features such as seizures or malformations. We suspected that strabismus might also be unusually frequent in this population and that it might be associated with ID groups affecting motor control. Methods We reviewed phenotypic descriptors, extracted from medical records, for a heterogeneous series of 222 probands with ID who had been enrolled in a study of clinical application of exome sequencing. We estimated the frequency of strabismus and other common clinical features and explored statistical associations between them. Data from Population Data British Columbia and Online Mendelian Inheritance in Man were also examined for confirmation of our observations. Results Strabismus had a higher prevalence among probands with ID than in the general population (odds ratio = 5.46). Moreover, probands with both ID and strabismus were more likely to have problems affecting motor control than those with ID and no strabismus (odds ratio = 2.84). Hypotonia was one of the most common motor control subgroups affecting the ID probands, and a frequent co-occurrence of strabismus and hypotonia was also observed (odds ratio = 2.51) and supported by related gene literature review. There was no evidence for associations between strabismus and other frequent clinical features. Conclusion Strabismus is a frequent feature in individuals with ID. The frequent co-occurrence of strabismus and motor control phenotypes, in particular hypotonia, suggests that a common cerebellar mechanism or pathway may underlie these phenotypes.

Genetic disorders are one of the leading causes of infant mortality and are frequent in neonatal intensive care units (NICUs). Rapid genome-wide sequencing (GWS; whole genome or exome sequencing (ES)), due to its diagnostic capabilities and immediate impacts on medical management, is becoming an appealing testing option in the NICU setting. RAPIDOMICS was a trio-based rapid ES pilot study of 25 babies with suspected genetic disorders in the BC Women's Hospital NICU. ES and bioinformatic analysis were performed after careful patient ascertainment. Trio analysis was performed using an in-house pipeline reporting variants in known disease-causing genes. Variants interpreted by the research team as definitely or possibly causal of the infant's phenotype were Sanger validated in a clinical laboratory. The average time to preliminary diagnosis was 7.2 days. Sanger validation was pursued in 15 patients for 13 autosomal dominant and 2 autosomal recessive disorders, with an overall diagnostic rate (partial or complete) of 60%.Conclusion: In total, 72% of patients enrolled had a genomic diagnosis achieved through ES, multi-gene panel testing or chromosomal microarray analysis. Among these, there was an 83% rate of significant and immediate impact on medical decision-making directly related to new knowledge of the diagnosis. Health service implementation challenges and successes are discussed. What is Known: • Rapid genome-wide sequencing in the neonatal intensive care setting has a greater diagnostic hit rate and impact on medical management than conventional genetic testing. However, the impact of consultation with genetics and patient ascertainment requires further investigation. What is New: • This study demonstrates the importance of genetic consultation and careful patient selection prior to pursuing exome sequencing (ES). • In total, 15/25 (60%) patients achieved a diagnosis through ES and 18/25 (72%) through ES, multi-gene panel testing or chromosomal microarray analysis with 83% of those having immediate effects on medical management.

Arrhythmogenic cardiomyopathy is a genetic heart muscle disorder characterized by fibro-fatty replacement of cardiomyocytes leading to life-threatening ventricular arrhythmias, heart failure and sudden cardiac death. Mutations in genes encoding cardiac junctional proteins are known to cause about half of cases, while remaining genetic causes are unknown. Using exome sequencing we identified two missense variants (p.H33N; p.H77Y) that were predicted to be damaging in the integrin-linked kinase (ILK) gene in two unrelated families. The p.H33N variant was found to be de novo. ILK links integrins and the actin cytoskeleton and is essential for the maintenance of normal cardiac function. Both of the new variants are located in the ILK ankyrin repeat domain, which binds to the first LIM domain of the adaptor proteins PINCH1 and PINCH2. In silico binding studies proposed that the human variants disrupt the ILK-PINCH complex. Recombinant mutant ILK expressed in H9c2 rat myoblast cells shows aberrant prominent cytoplasmic localization compared to the wildtype. Expression of human wild-type and mutant ILK under the control of the cardiac-specific cmlc2 promotor in ipebrafish shows that p.H77Y and p.P70L, a variant previously reported in a dilated cardiomyopathy family, cause cardiac dysfunction and death by about 2–3 weeks of age. Our findings provide genetic and functional evidence that ILK is a cardiomyopathy disease gene and highlight its relevance for diagnosis and genetic counselling of inherited cardiomyopathies.

A decade ago, we described novel de novo submicroscopic deletions of chromosome 14q11.2 in three children with developmental delay, cognitive impairment, and similar dysmorphic features, including widely-spaced eyes, short nose with flat nasal bridge, long philtrum, prominent Cupid's bow of the upper lip, full lower lip, and auricular anomalies. We suggested that this constituted a new multiple congenital anomaly-intellectual disability syndrome due to defects in CHD8 and/or SUPT16H. The three patients in our original cohort were between 2 years and 3 years of age at the time. Here we present a fourth patient and clinical updates on our previous patients. To document the longitudinal course more fully, we integrate published reports of other patients and describe genotype-phenotype correlations among them. Children with the disorder present with developmental delay, intellectual disability, and/or autism spectrum disorder in addition to characteristic facies. Gastrointestinal and sleep problems are notable. The identification of multiple patients with the same genetic defect and characteristic clinical phenotype, confirms our suggestion that this is a syndromic disorder caused by haploinsufficiency or heterozygous loss of function of CHD8.

Clinical use of genome-wide sequencing (GWS) requires pre-test genetic counseling, but the availability of genetic counseling is limited. We developed an interactive online decision-support tool, DECIDE, to make genetic counseling, patient education, and decision support more readily available. We performed a non-inferiority trial comparing DECIDE to standard genetic counseling to assess the clinical value of DECIDE for pre-GWS counseling. One hundred and six parents considering GWS for their children with epilepsy were randomized to conventional genetic counseling or DECIDE. Following the intervention, we measured parents' knowledge and empowerment and asked their opinions about using DECIDE. Both DECIDE and conventional genetic counseling significantly increased parents' knowledge, with no difference between groups. Empowerment also increased but by less than 2% in each group. Parents liked using DECIDE and found it useful; 81% would recommend it to others; 49% wished to use it along with a genetic counselor; 26% of parents preferred to see a genetic counselor; 7% preferred DECIDE alone; and 18% had no preference. DECIDE appears equivalent to genetic counseling at conveying information. In addition, it was highly acceptable to the majority of study participants, many of whom indicated that it was useful to their decision-making. Use of DECIDE as a pre-test tool may extend genetic counseling resources.

Genomic testing is becoming routine for diagnosing rare childhood genetic disease. Evidence underlying sustainable implementation is limited, focusing on short-term endpoints such as diagnostic yield, unable to fully characterize patient and family valued outcomes. Although genomic testing is becoming widely available, evidentiary and outcomes uncertainty persist as key challenges for implementation. We examine whether the current evidence base reflects public tolerance for uncertainty for genomics to diagnose rare childhood genetic disease. We conducted focus groups with general population parents in Vancouver, Canada, and Oxford, United Kingdom, to discuss expectations and concerns related to genomic testing to diagnose rare childhood genetic disease. Applying a purposive sampling technique, recruitment continued until thematic saturation was reached. Transcripts were analysed using thematic analysis. Thirty-three parents participated across four focus groups. Participants valued causal diagnoses alongside management strategies to improve patient health and wellbeing. Further, participants valued expanding the evidence base to reduce evidentiary uncertainty while ensuring security of information. Willingness to pay out of pocket for testing reflected perceived familial health benefit. Diagnostic yield fails to fully capture valued outcomes, and efforts to resolve uncertainty better reflect public priorities. Evaluations of genomic testing that fully integrate valued endpoints are necessary to ensure consistency with best practices and public willingness to accept the uncertain familial benefit.

Introduction Genome-wide sequencing (exome or whole genome) is transforming the care and management of paediatric patients with a rare disease because of its diagnostic capabilities. Genome-wide sequencing is most effective when both parents and the child are sequenced as a trio. Genetic counselling is recommended for all families considering genome-wide sequencing. Although telehealth is well established in genetic counselling for hereditary cancer and prenatal genetics, its use with genome-wide sequencing has not been well studied. The CAUSES Clinic at BC Children’s and Women’s Hospitals was a translational paediatric trio-based genome-wide sequencing initiative. Pre-test genetic counselling via telehealth (at a clinical site near the family’s residence) was offered to families who had been previously evaluated by a clinical geneticist. We report on the first 300 families seen in the CAUSES clinic and compare health services implementation issues of families seen via telehealth versus on-site. Methods Demographics, cost to families (travel and time), time to first appointment, complete trio sample accrual and diagnostic rates were studied. Results Of the 300 patients, 58 (19%) were seen via telehealth and 242 (81%) were seen on-site for pre-test counselling. The mean time to completion of accrual of trio samples in the telehealth group was 56.3 (standard deviation ±87.3) days versus 18.9 (standard deviation ±62.4) days in the onsite group ( p −16). The mean per-family estimated actual or potential travel/time cost savings were greater in the telehealth group (Can$987; standard deviation = Can$1151) than for those seen on-site (Can$305; standard deviation = Can$589) ( p = 0.0004). Conclusions Telehealth allowed for access to genome-wide sequencing for families in remote communities and for them to avoid significant travel and time costs; however, there was a significant delay to accrual of the complete trio samples in the telehealth group, impacting on time of result reporting and delaying diagnoses for families for whom genome-wide sequencing was diagnostic.

Many parents are motivated to pursue genome-wide (exome or genome) sequencing to find a diagnosis for their child with a suspected but undiagnosed genetic condition. However, the impact of the genomic test extends beyond the provision of results and the so-called 'diagnostic odyssey'. Our goal was to quantify post-test decisional regret and characterize long-term, post-test experiences and unmet needs of the parents of children with suspected genetic diseases after they had received the results of genome-wide sequencing. Study participants were parents of children who underwent trio genome-wide sequencing as part of the CAUSES research study at Children's & Women's Health Centre of British Columbia. About half of the participants received a definite or likely genetic diagnosis after clinical interpretation of the genome-wide sequencing results. Parents who participated in the current study (n = 121) completed the Decisional Regret Scale four weeks after receiving results. A subset of these parents (n = 32) had semi-structured interviews a median of 7 months (range 3-20 months) after results disclosure and post-test genetic counseling. Most parents expressed either no regret or mild regret about having undergone genome-wide sequencing on both the Decisional Regret Scale and in the interviews. Parents whose children did not receive a genetic diagnosis were slightly more likely to have decisional regret on this quantitative scale. Analysis of transcribed interviews revealed the following major themes: (a) a lack of decisional conflict around having the testing; (b) a lack of decisional regret post-testing; (c) expressions of both relief and continued uncertainty around the meaning of a genetic diagnosis; (d) expression of initial disappointment and evolving interpretation surrounding a result yielding no genetic diagnosis; and (e) needing time to absorb the test results. Our results suggest that parents need time to absorb the testing results and that long-term post-test counseling, including acknowledging feelings of relief, loss, and disappointment, may help parents adapt to the genomic test results and assist families to anticipate and plan for the next steps in their child's medical trajectory, whether or not a diagnosis is found.

Cerebral palsy (CP) is a debilitating condition characterized by abnormal movement or posture, beginning early in development. Early family and twin studies and more recent genomic investigations clearly demonstrate that genetic factors of major effect contribute to the etiology of CP. Most copy number variants and small alterations of nucleotide sequence that cause CP arise as a result of de novo mutations, so studies that estimate heritability on basis of recurrence frequency within families substantially underestimate genetic contributions to the etiology. At least 4% of patients with typical CP have disease-causing CNVs, and at least 14% have disease-causing single nucleotide variants or indels. The rate of pathogenic genomic lesions is probably more than twice as high among patients who have atypical CP, i.e., neuromotor dysfunction with additional neurodevelopmental abnormalities or malformations, or with MRI findings and medical history that are not characteristic of a perinatal insult. Mutations of many different genetic loci can produce a CP-like phenotype. The importance of genetic variants of minor effect and of epigenetic modifications in producing a multifactorial predisposition to CP is less clear. Recognizing the specific cause of CP in an affected individual is essential to providing optimal clinical management. An etiological diagnosis provides families an “enhanced compass” that improves overall well-being, facilitates access to educational and social services, permits accurate genetic counseling, and, for a subset of patients such as those with underlying inherited metabolic disorders, may make precision therapy that targets the pathophysiology available. Trio exome sequencing with assessment of copy number or trio genome sequencing with bioinformatics analysis for single nucleotide variants, indels, and copy number variants is clinically indicated in the initial workup of CP patients, especially those with additional malformations or neurodevelopmental abnormalities.

Identifying genetic mosaicism is important in establishing a diagnosis, assessing recurrence risk, and providing accurate genetic counseling. Next-generation sequencing has allowed for the identification of mosaicism at levels below those detectable by conventional Sanger sequencing or chromosomal microarray analysis. The CAUSES Clinic was a pediatric translational trio-based genome-wide (exome or genome) sequencing study of 500 families (531 children) with suspected genetic disease at BC Children's and Women's Hospitals. Here we present 12 cases of apparent mosaicism identified in the CAUSES cohort: nine cases of parental mosaicism for a disease-causing variant found in a child and three cases of mosaicism in the proband for a de novo variant. In six of these cases, there was no evidence of mosaicism on Sanger sequencing—the variant was not detected on Sanger sequencing in three cases, and it appeared to be heterozygous in three others. These cases are examples of six clinical manifestations of mosaicism: a proband with classical clinical features of mosaicism (e.g., segmental abnormalities of skin pigmentation or asymmetrical growth of bilateral body parts), a proband with unusually mild manifestations of a disease, a mosaic proband who is clinically indistinguishable from the constitutive phenotype, a mosaic parent with no clinical features of the disease, a mosaic parent with mild manifestations of the disease, and a family in which both parents are unaffected and two siblings have the same disease-causing constitutional mutation. Our data demonstrate the importance of considering the possibility of mosaicism whenever exome or genome sequencing is performed and that its detection via genome-wide sequencing can permit more accurate genetic counseling.

Monoamine neurotransmitter disorders present predominantly with neurologic features, including dystonic or dyskinetic cerebral palsy and movement disorders. Genetic conditions that lead to secondary defects in the synthesis, catabolism, transport, and metabolism of biogenic amines can lead to neurotransmitter abnormalities, which can present with similar features. Eleven patients with secondary neurotransmitter abnormalities were enrolled between 2011 and 2015. All patients underwent research-based whole exome and/or whole genome sequencing (WES/WGS). A trial of treatment with levodopa/carbidopa and 5-hydroxytryptophan was initiated. In six families with abnormal neurotransmitter profiles and neurological phenotypes, variants in known disease-causing genes (KCNJ6, SCN2A, CSTB in 2 siblings, NRNX1, KIF1A and PAK3) were identified, while one patient had a variant of uncertain significance in a candidate gene (DLG4) that may explain her phenotype. In 3 patients, no compelling candidate genes were identified. A trial of neurotransmitter replacement therapy led to improvement in motor and behavioral symptoms in all but two patients. The patient with KCNJ6 variant did not respond to L-dopa therapy, but rather experienced increased dyskinetic movements even at low dose of medication. The patient's symptoms harboring the NRNX1 deletion remained unaltered. This study demonstrates the utility of genome-wide sequencing in further understanding the etiology and pathophysiology of neurometabolic conditions, and the potential of secondary neurotransmitter deficiencies to serve as novel therapeutic targets. As there was a largely favorable response to therapy in our case series, a careful trial of neurotransmitter replacement therapy should be considered in patients with cerebrospinal fluid (CSF) monoamines below reference range.

Neurofibromatosis type 2 is a neurogenetic disorder with an incidence of about 1:33.000. Hallmarks are bilateral benign vestibular schwannomas, which can lead to deafness or brainstem compression. Volumetric tumor measurements are essential to assess the efficacy of new therapies. We present a statistical and methodical comparison of three volumetric image analysis tools. We performed volumetric measurements on phantoms with predefined volumes (0.1 to 8.0 ml) and tumors seen on 32 head MRI scans from eight NF2 patients with BrainLab, ITK-Snap, or OsiriX. The software was compared with regard to accuracy and reproducibility of the measurements and time required for analysis. The mean volume estimated by all three software programs differed significantly from the true volume of the phantoms, but OsiriX and BrainLab gave estimates that were not significantly different from each other. For the actual tumors, the estimated volumes with all three software tools showed a low coefficient of variability, but the mean volume estimates differed among the tools. OsiriX showed the shortest analysis time. Volumetric assessment of MRI images is associated to an intrinsic risk of miscalculation. For precise volumes it is mandatory to use the same volumetric tools for all measurements.

Short tandem repeat (STR) expansions cause several neurological and neuromuscular disorders. Screening for STR expansions in genome-wide (exome and genome) sequencing data can enable diagnosis, optimal clinical management/treatment, and accurate genetic counselling of patients with repeat expansion disorders. We assessed the performance of lobSTR, HipSTR, RepeatSeq, ExpansionHunter, TREDPARSE, GangSTR, STRetch, and exSTRa – bioinformatics tools that have been developed to detect and/or genotype STR expansions – on experimental and simulated genome sequence data with known STR expansions aligned using two different aligners, Isaac and BWA. We then adjusted the parameter settings to optimize the sensitivity and specificity of the STR tools and fed the optimized results into a machine-learning decision tree classifier to determine the best combination of tools to detect full mutation expansions with high diagnostic sensitivity and specificity. The decision tree model supported using ExpansionHunter’s full mutation calls with those of either STRetch or exSTRa for detection of full mutations with precision, recall, and F1-score of 90%, 100%, and 95%, respectively.We used this pipeline to screen the BWA-aligned exome or genome sequence data of 306 families of children with suspected genetic disorders for pathogenic expansions of known disease STR loci. We identified 27 samples, 17 with an apparent full-mutation expansion of the AR, ATXN1, ATXN2, ATXN8, DMPK, FXN, HTT, or TBP locus, nine with an intermediate or premutation allele in the FMR1 locus, and one with a borderline allele in the ATXN2 locus. We report the concordance between our bioinformatics findings and the clinical PCR results in a subset of these samples. Implementation of our bioinformatics workflow can improve the detection of disease STR expansions in exome and genome sequence diagnostics and enhance clinical outcomes for patients with repeat expansion disorders.

Purpose Clinical diagnostic genome-wide (exome or genome) sequencing (GWS) in British Columbia requires funding approval by a provincial agency on a case-by-case basis. The CAUSES Clinic was a pediatric translational trio-based GWS study at BC Children's and Women's Hospitals. Referrals to the CAUSES Clinic were made through a Genomic Consultation Service (GCS), a multidisciplinary team led by genetic counsellors that provided advice regarding genomic testing for physicians considering GWS for their patients. Here we review the outcomes of the GCS, focusing on patients not recommended for the CAUSES Study. Methods Demographic, clinical, and testing data were abstracted from patient charts. Logistic regression analysis was used to explore associations between demographic and clinical variables and two outcomes: the type of recommendation and referring physicians’ decisions to follow the recommendation. Results Of 972 GCS referrals, 248 patients were not referred to the CAUSES Study. GWS (vs. a targeted test; e.g. multi-gene panel) was more likely to be recommended to physicians of patients with ID than physicians of patients without ID (OR = 2.98; 95% CI = 1.46 to 6.27; n = 149). In total, 40% of physicians who were recommended to pursue clinical genomic testing submitted an application for funding approval; 71% of applications were approved for funding. Among approved tests, 50% resulted in a diagnosis, including 33% of targeted tests and 82% of GWS tests (χ2 (1) = 5.0, p = 0.026). Conclusion The GCS provided an effective model in which physicians can interface with genetic specialists, including genetic counsellors, to facilitate appropriate genomic test selection.