Randomized prospective evaluation of genome sequencing versus standard-of-care as a first molecular diagnostic test.

PURPOSE: To evaluate the diagnostic yield and clinical relevance of clinical genome sequencing (cGS) as a first genetic test for patients with suspected monogenic disorders. METHODS: We conducted a prospective randomized study with pediatric and adult patients recruited from genetics clinics at Massachusetts General Hospital who were undergoing planned genetic testing. Participants were randomized into two groups: standard-of-care genetic testing (SOC) only or SOC and cGS. RESULTS: Two hundred four participants were enrolled, 202 were randomized to one of the intervention arms, and 99 received cGS. In total, cGS returned 16 molecular diagnoses that fully or partially explained the indication for testing in 16 individuals (16.2% of the cohort, 95% confidence interval [CI] 8.9-23.4%), which was not significantly different from SOC (18.2%, 95% CI 10.6-25.8%, P = 0.71). An additional eight molecular diagnoses reported by cGS had uncertain relevance to the participant's phenotype. Nevertheless, referring providers considered 20/24 total cGS molecular diagnoses (83%) to be explanatory for clinical features or worthy of additional workup. CONCLUSION: cGS is technically suitable as a first genetic test. In our cohort, diagnostic yield was not significantly different from SOC. Further studies addressing other variant types and implementation challenges are needed to support feasibility and utility of broad-scale cGS adoption.

A Pooled Electronic Consultation Program to Improve Access to Genetics Specialists.

Innovative service delivery models are needed to increase access to genetics specialists. Electronic consultation (e-Consult) programs can connect clinicians with specialists. At Massachusetts General Hospital, an e-Consult service was created to address genomics-related questions. In its first year, the e-Consult service triaged 153 requests and completed 122 in an average of 3.2 days. Of the 95 e-Consults with actionable recommendations, there was documentation that most ordering clinicians followed through (82%). A variety of providers used the service, although the majority (77%) were generalists. E-Consult models should be considered as one way to increase access to genetics care.

Clinical Implementation of Combined Monogenic and Polygenic Risk Disclosure for Coronary Artery Disease.

BACKGROUND: State-of-the-art genetic risk interpretation for a common complex disease such as coronary artery disease (CAD) requires assessment for both monogenic variants-such as those related to familial hypercholesterolemia-as well as the cumulative impact of many common variants, as quantified by a polygenic score. OBJECTIVES: The objective of the study was to describe a combined monogenic and polygenic CAD risk assessment program and examine its impact on patient understanding and changes to clinical management. METHODS: Study participants attended an initial visit in a preventive genomics clinic and a disclosure visit to discuss results and recommendations, primarily via telemedicine. Digital postdisclosure surveys and chart review evaluated the impact of disclosure. RESULTS: There were 60 participants (mean age 51 years, 37% women, 72% with no known CAD), including 30 (50%) referred by their cardiologists and 30 (50%) self-referred. Two (3%) participants had a monogenic variant pathogenic for familial hypercholesterolemia, and 19 (32%) had a high polygenic score in the top quintile of the population distribution. In a postdisclosure survey, both the genetic test report (in 80% of participants) and the discussion with the clinician (in 89% of participants) were ranked as very or extremely helpful in understanding the result. Of the 42 participants without CAD, 17 or 40% had a change in management, including statin initiation, statin intensification, or coronary imaging. CONCLUSIONS: Combined monogenic and polygenic assessments for CAD risk provided by preventive genomics clinics are beneficial for patients and result in changes in management in a significant portion of patients.

Challenges and Errors in Genetic Testing: The Fifth Case Series.

PURPOSE: In this ongoing case series, 33 genetic testing cases are documented in which tests were recommended, ordered, interpreted, or used incorrectly and/or in which clinicians faced challenges related to history/reports provided by patients or laboratories. METHODS: An invitation to submit cases of challenges or errors in genetic testing was issued to the general National Society of Genetic Counselors Listserv, the National Society of Genetic Counselors Cancer Special Interest Group members, as part of a case series with Precision Oncology News, and via social media (i.e., Facebook, Twitter, LinkedIn). Deidentified clinical documentation was requested and reviewed when available. Thirty-three cases were submitted, reviewed, and accepted. A thematic analysis was performed. Submitters were asked to approve cases before submission. RESULTS: All cases took place in the United States, involved hereditary cancer testing and/or findings in cancer predisposition genes, and involved medical-grade genetic testing, direct-to-consumer testing, or research genetic testing. In 9 cases, test results were misinterpreted, leading to incorrect screening or risk-reducing procedures being performed/recommended. In 5 cases, incorrect or unnecessary testing was ordered/recommended. In 3 cases, incorrect clinical diagnoses were made, or opportunities for diagnoses were delayed. In 3 cases, errors or challenges arose related to medical intervention after testing or reported genetic diagnosis. In 2 cases, physicians provided incorrect information related to the inheritance pattern of a syndrome. In 2 cases, there were challenges related to the interpretation of genetic variants. In 2 cases, challenges arose after direct-to-consumer testing. One case involved test results that should never have been reported based on sample quality. In 1 case, a patient presented a falsified test result. In 5 cases, multiple errors were made. DISCUSSION: As genetic testing continues to become more complicated and common, it is critical that patients and nongenetics providers have access to accurate and timely genetic counseling information. Even as multiple medical bodies highlight the value of genetic counselors (GCs), tension exists in the genomics community as GCs work toward licensure and Medicare provider status. It is critical that health care communities leverage, rather than restrict, the expertise and experience of GCs so that patients can benefit from, and not be harmed by, genetic testing. In order to responsibly democratize genomics, it will be important for genetics and nongenetic health care providers to collaborate and use alternative service delivery models and technology solutions at point of care. To deliver on the promise of precision medicine, accurate resources and tools must be utilized.

From Theory to Reality: Establishing a Successful Kidney Genetics Clinic in the Outpatient Setting.

Background: Genetic testing in nephrology is increasingly described in the literature and several groups have suggested significant clinical benefit. However, studies to date have described experience from established genetic testing centers or from externally funded research programs. Methods: We established a de novo kidney genetics clinic within an academic adult general nephrology practice. Key features of this effort included a pipeline for internal referrals, flexible scheduling, close coordination between the nephrologist and a genetic counselor, and utilization of commercial panel-based testing. Over the first year, we examined the outcomes of genetic testing, the time to return of genetic testing, and out-of-pocket cost to patients. Results: Thirty patients were referred and 23 were evaluated over the course of five clinic sessions. Nineteen patients underwent genetic testing with new diagnoses in nine patients (47%), inconclusive results in three patients (16%), and clearance for kidney donation in two patients (11%). On average, return of genetic results occurred 55 days (range 9-174 days) from the day of sample submission and the average out-of-pocket cost to patients was $155 (range $0-$1623). Conclusions: We established a kidney genetics clinic, without a pre-existing genetics infrastructure or dedicated research funding, that identified a new diagnosis in approximately 50% of patients tested. This study provides a clinical practice model for successfully incorporating genetic testing into ambulatory nephrology care with minimal capital investment and limited financial effect on patients.

Expanding the phenotypic spectrum associated with OPHN1 variants.

Genomic sequencing has allowed for the characterization of new gene-to-disease relationships, as well as the identification of variants in established disease genes in patients who do not fit the classically-described phenotype. This is especially true in rare syndromes where the clinical spectrum is not fully known. After a lengthy and costly diagnostic odyssey, patients with atypical presentations may be left with many questions even after a genetic diagnosis is identified. We present a 22-year old male with hypotonia, developmental delay, seizure disorder, and dysmorphic facial features who enrolled in our rare disease research center at 18 years of age, where exome sequencing revealed a novel, likely pathogenic variant in the OPHN1 gene. Through efforts by the study team and collaborations with the larger genetics community, contacts with other families with OPHN1 variants were eventually made, and outreach by these families expanded the patient network. This partnership between families and researchers facilitated the gathering of phenotypic information, allowing for comparison of clinical presentations among three new patients and those previously reported in the literature. These comparisons found previously unreported commonalities between the newly identified patients, such as the presence of otitis media and the lack of genitourinary abnormalities (i.e. hypoplastic scrotum, microphallus, cryptorchidism), which had been noted to be classic features of patients with OPHN1 variants. As genomic sequencing becomes more common, connecting patients with novel variants in the same gene will facilitate phenotypic analysis and continue to refine the clinical spectrum associated with that gene.

SLC6A1 Mutation and Ketogenic Diet in Epilepsy With Myoclonic-Atonic Seizures.

BACKGROUND: Epilepsy with myoclonic-atonic seizures, also known as myoclonic-astatic epilepsy or Doose syndrome, has been recently linked to variants in the SLC6A1 gene. Epilepsy with myoclonic-atonic seizures is often refractory to antiepileptic drugs, and the ketogenic diet is known for treating medically intractable seizures, although the mechanism of action is largely unknown. We report a novel SLC6A1 variant in a patient with epilepsy with myoclonic-atonic seizures, analyze its effects, and suggest a mechanism of action for the ketogenic diet. METHODS: We describe a ten-year-old girl with epilepsy with myoclonic-atonic seizures and a de novo SLC6A1 mutation who responded well to the ketogenic diet. She carried a c.491G>A mutation predicted to cause p.Cys164Tyr amino acid change, which was identified using whole exome sequencing and confirmed by Sanger sequencing. High-resolution structural modeling was used to analyze the likely effects of the mutation. RESULTS: The SLC6A1 gene encodes a transporter that removes gamma-aminobutyric acid from the synaptic cleft. Mutations in SLC6A1 are known to disrupt the gamma-aminobutyric acid transporter protein 1, affecting gamma-aminobutyric acid levels and causing seizures. The p.Cys164Tyr variant found in our study has not been previously reported, expanding on the variants linked to epilepsy with myoclonic-atonic seizures. CONCLUSION: A 10-year-old girl with a novel SLC6A1 mutation and epilepsy with myoclonic-atonic seizures had an excellent clinical response to the ketogenic diet. An effect of the diet on gamma-aminobutyric acid reuptake mediated by gamma-aminobutyric acid transporter protein 1 is suggested. A personalized approach to epilepsy with myoclonic-atonic seizures patients carrying SLC6A1 mutation and a relationship between epilepsy with myoclonic-atonic seizures due to SLC6A1 mutations, GABAergic drugs, and the ketogenic diet warrants further exploration.