Germline PTCH1: c.361_362insAlu alteration identified by comprehensive exome and RNA sequencing in a patient with Gorlin syndrome.

Gorlin syndrome can be caused by pathogenic/likely pathogenic (P/LP) variants in the tumor suppressor gene PTCH1 (9q22.1-q31), which encodes the receptor for the sonic hedgehog (SHH) ligand. We present a 12-month-old boy clinically diagnosed with Gorlin syndrome who was found to have significantly delayed development, palmar pitting, palmar and plantar keratosis, short hands, frontal bossing, coarse face, hypertelorism, a bifid rib, misaligned and missing teeth, and SHH-activated medulloblastoma. Genetic testing, including a pediatric cancer panel and genome sequencing with peripheral blood, failed to identify any P/LP variants in PTCH1. Paired tumor/normal exome sequencing was performed, which identified a germline NM_000264.5 (PTCH1): c.361_362ins? alteration through manual review of sequencing reads. Clinical RNA sequencing further demonstrated an Alu insertion at this region (PTCH1: c.361_362insAlu), providing molecular confirmation of Gorlin syndrome. This finding exemplifies a unique mechanism for PTCH1 disruption in the germline and highlights the importance of comprehensive analysis, including manual review of DNA sequencing reads and the utility of RNA analysis to detect variant types which may not be identified by routine genetic screening techniques.

Detection of a novel gross deletion in the UNC13D gene ends the diagnostic odyssey for a family with familial hemophagocytic lymphohistiocytosis 3.

BACKGROUND: Familial hemophagocytic lymphohistiocytosis (FHL) is an immunological disorder characterized by overactivation of macrophages and T lymphocytes. This autosomal recessive condition has been characterized into multiple types depending on the genetic etiology. FHL type 3 is associated with bi-allelic pathogenic variants in the UNC13D gene. CASE PRESENTATION: We present a 12-year diagnostic odyssey for a family with FHL that signifies the advances of FHL genetic testing in a clinical genetic diagnostic laboratory setting. We describe the first case of a large UNC13D gross deletion in trans to a nonsense variant in a family with FHL3, which may have been mediated by Alu elements within introns 12 and 25 of the UNC13D gene. CONCLUSIONS: This case highlights the importance of re-evaluating past genetic testing for a patient and family as test technology evolves in order to end a diagnostic odyssey.

Genetic counseling for the dystrophinopathies-Practice resource of the National Society of Genetic Counselors.

The dystrophinopathies encompass the phenotypically variable forms of muscular dystrophy caused by pathogenic variants in the DMD gene. The dystrophinopathies include the most common inherited muscular dystrophy among 46,XY individuals, Duchenne muscular dystrophy, as well as Becker muscular dystrophy and other less common phenotypic variants. With increased access to and utilization of genetic testing in the diagnostic and carrier setting, genetic counselors and clinicians in diverse specialty areas may care for individuals with and carriers of dystrophinopathy. This practice resource was developed as a tool for genetic counselors and other health care professionals to support counseling regarding dystrophinopathies, including diagnosis, health risks and management, psychosocial needs, reproductive options, clinical trials, and treatment. Genetic testing efforts have enabled genotype/phenotype correlation in the dystrophinopathies, but have also revealed unexpected findings, further complicating genetic counseling for this group of conditions. Additionally, the therapeutic landscape for dystrophinopathies has dramatically changed with several FDA-approved therapeutics, an expansive research pathway, and numerous clinical trials. Genotype-phenotype correlations are especially complex and genetic counselors' unique skill sets are useful in exploring and explaining this to families. Given the recent advances in diagnostic testing and therapeutics related to dystrophinopathies, this practice resource is a timely update for genetic counselors and other healthcare professionals involved in the diagnosis and care of individuals with dystrophinopathies.

Understanding and interpretation of a variant of uncertain significance (VUS) genetic test result by pediatric providers who do not specialize in genetics.

The advancement of genetic testing technologies has allowed for better diagnosis and management of patients, but also results in more variants of uncertain significance (VUSs) due to the increased number of genes being analyzed. There are more genetic tests available and more providers who do not specialize in genetics ordering genetic testing, but few studies examining how providers who do not specialize in genetics interpret VUSs. This study surveyed pediatric providers at a midwestern pediatric care center who do not specialize in genetics about their understanding of a mock genetic test report with a VUS result and whether their understanding of the result was associated with experience ordering genetic tests. Participants' preferences about content of the report and steps taken to understand the result were also examined. Of the 51 participants, 33% correctly answered both knowledge questions about the VUS result: one asking them to interpret the result and one asking them how they would explain the result to the patient. There was no association between answering both knowledge questions correctly and types of previous genetic tests ordered (p > .1 for 8 types of genetic tests), having received a genetic test report with a VUS result (p = .58), having referred patients to a genetics professional (p = .74), or feeling comfortable discussing a positive, negative, or VUS genetic test result (p > .4). This suggests that having previous experience ordering genetic tests does not contribute to the participants' knowledge about a variant of uncertain significance. Most participants reported that the amount of information in each section of the mock report was adequate. Participants were likely to reference multiple resources to better understand a VUS result, including published literature (82%), gene-specific databases (67%), and colleagues (63%). While these results cannot be generalized to all institutions, institutions can use the two knowledge questions to determine participants' understanding of genetic test results. This will help healthcare institutions determine methods that will best aide their providers who order genetic testing but do not specialize in genetics in learning more about the genetic testing process and better utilize results to improve patient care.

Reduction of Health Care Costs and Improved Appropriateness of Incoming Test Orders: the Impact of Genetic Counselor Review in an Academic Genetic Testing Laboratory.

The goal of this study was to evaluate the impact of genetic counselor (GC) review of incoming test orders received in an academic diagnostic molecular genetics laboratory. The GC team measured the proportion of orders that could be modified to improve efficiency or sensitivity, tracked provider uptake of GC proposed testing changes, and calculated the health care dollar savings resulting from GC intervention. During this 6-month study, the GC team reviewed 2367 incoming test orders. Of these, 109 orders (4.6%) were flagged for review for potentially inefficient or inappropriate test ordering. These flagged orders corresponded to a total of 51 cases (1-5 orders for each patient), representing 54 individuals and including 3 sibling pairs. The GC team proposed a modification for each flagged case and the ordering providers approved the proposed change for 49 of 51 cases (96.08%). For the 49 modifications, the cost savings totaled $98,750.64, for an average of $2015.32 saved per modification. This study provides evidence of the significant contribution of genetic counselors in a laboratory setting and demonstrates the benefit of laboratories working with ordering providers to identify the best test for their patients. The review of test orders by a genetic counselor both improves genetic test ordering strategies and decreases the amount of health care dollars spent on genetic testing.

Identification of Biallelic dystrophin gene variants during maternal carrier testing for Becker muscular dystrophy and review of the DMD exon 49-51 deletion phenotype.

BACKGROUND: Dystrophinopathies are X-linked recessive conditions caused by pathogenic variants in the dystrophin (DMD) gene. In a family that included two boys with Becker muscular dystrophy (BMD) due to a DMD deletion of exons 45-47, maternal carrier testing unexpectedly identified biallelic DMD deletions of exons 45-47 and 49-51. METHODS: The patient's mild phenotype in the setting of biallelic DMD variants prompted further investigation of the exon 49-51 deletion in particular, via literature review and retrospective chart review of patients who have been evaluated in our institution's comprehensive neuromuscular center and/or diagnosed in our clinical genetic testing laboratory. RESULTS: To our knowledge, this is only the fifth case of confirmed biallelic DMD variants in a female. In males, the DMD exon 49-51 deletion appears to result in a mild BMD phenotype with low or normal creatine kinase levels. This deletion comprised 19% (4/21) of dystrophinopathies diagnosed by chromosomal microarray (CMA) in males during the past ten years in our clinical laboratory. Most individuals identified by chart review were diagnosed through CMA, despite the fact that microarray was genome-wide and not DMD-specific. This case raised important genetic counseling issues. CONCLUSION: The DMD exon 49-51 deletion appears to cause a variable but generally mild BMD phenotype. Its relatively frequent detection by CMA suggests it may be underdiagnosed.

Adverse Events in Genetic Testing: The Fourth Case Series.

PURPOSE: In this ongoing national case series, we document 25 new genetic testing cases in which tests were recommended, ordered, interpreted, or used incorrectly. METHODS: An invitation to submit cases of adverse events 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, private genetic counselor laboratory groups, and via social media platforms (i.e., Facebook, Twitter, LinkedIn). Examples highlighted in the invitation included errors in ordering, counseling, and/or interpretation of genetic testing and did not limit submissions to cases involving genetic testing for hereditary cancer predisposition. Clinical documentation, including pedigree, was requested. Twenty-six cases were accepted, and a thematic analysis was performed. Submitters were asked to approve the representation of their cases before manuscript submission. RESULTS: All submitted cases took place in the United States and were from cancer, pediatric, preconception, and general adult settings and involved both medical-grade and direct-to-consumer genetic testing with raw data analysis. In 8 cases, providers ordered the wrong genetic test. In 2 cases, multiple errors were made when genetic testing was ordered. In 3 cases, patients received incorrect information from providers because genetic test results were misinterpreted or because of limitations in the provider's knowledge of genetics. In 3 cases, pathogenic genetic variants identified were incorrectly assumed to completely explain the suspicious family histories of cancer. In 2 cases, patients received inadequate or no information with respect to genetic test results. In 2 cases, result interpretation/documentation by the testing laboratories was erroneous. In 2 cases, genetic counselors reinterpreted the results of people who had undergone direct-to-consumer genetic testing and/or clarifying medical-grade testing was ordered. DISCUSSION: As genetic testing continues to become more common and complex, it is clear that we must ensure that appropriate testing is ordered and that results are interpreted and used correctly. Access to certified genetic counselors continues to be an issue for some because of workforce limitations. Potential solutions involve action on multiple fronts: new genetic counseling delivery models, expanding the genetic counseling workforce, improving genetics and genomics education of nongenetics health care professionals, addressing health care policy barriers, and more. Genetic counselors have also positioned themselves in new roles to help patients and consumers as well as health care providers, systems, and payers adapt to new genetic testing technologies and models. The work to be done is significant, but so are the consequences of errors in genetic testing.

Attitudes of parents of children with serious health conditions regarding residual bloodspot use.

BACKGROUND/OBJECTIVES: Studies have shown that the general public is supportive of newborn screening (NBS) and supportive of the storage and use of residual bloodspots for quality assurance and biomedical research. However, the attitudes of parents of children with serious health conditions have not been assessed. In this study, we assessed attitudes of parents with children who have phenylketonuria (PKU) and leukemia towards NBS and storage and use of residual bloodspots for research. METHODS: A total of 49 individuals were recruited and responded to a validated 41-item survey regarding NBS and the retention and use of residual bloodspots. Of these participants, 22 had a child with PKU and 27 had a child with leukemia. We compared their responses to those of 1,927 individuals from the general public obtained in a previous study using the same survey instrument. RESULTS/CONCLUSIONS: We found that parents of children with a serious health condition had higher levels of support than the general public towards the use of residual NBS samples for research but similar attitudes regarding choice and privacy protections. It is important to assess the attitudes of various stakeholders for policy development.