Genome sequencing detects a wide range of clinically relevant copy number variants and other genomic alterations
James KN, Chowdhury S, Ding Y, Batalov S, Watkins K, Kwon YH, Van Der Kraan L, Ellsworth K, Kingsmore SF, Guidugli L.
Genet Med. 2023 Oct 20:101006. doi: 10.1016/j.gim.2023.101006. Online ahead of print.
PURPOSE: Copy number variants (CNVs) and other non-SNV/indel variant types contribute an important proportion of diagnoses in individuals with suspected genetic disease. This study describes the range of such variants detected by genome sequencing (GS).
METHODS: For a pediatric cohort of 1032 participants undergoing clinical GS, we characterize the CNVs and other non-SNV/indel variant types that were reported, including aneuploidies, mobile element insertions, and uniparental disomies, and we describe the bioinformatic pipeline used to detect these variants.
RESULTS: Together, these genetic alterations accounted for 15.8% of reported variants. Notably, 67.9% of these were deletions, 32.9% of which overlapped a single gene, and many deletions were reported together with a second variant in the same gene in cases of recessive disease. A retrospective medical record review in a subset of this cohort revealed that up to six additional genetic tests were ordered in 68% (26/38) of cases, some of which failed to report the CNVs/rare variants reported on GS.
CONCLUSION: GS detected a broad range of reported variant types, including CNVs ranging in size from 1 Kb to 46 Mb.
October 20, 2023
RPM for NICU and PICU
Rapid Whole-Genomic Sequencing and a Targeted Neonatal Gene Panel in Infants With a Suspected Genetic Disorder
Maron JL, Kingsmore S, Gelb BD, Vockley J, Wigby K, Bragg J, Stroustrup A, Poindexter B, Suhrie K, Kim J, Diacovo T, Powell CM, Trembath A, Guidugli L, Ellsworth KA, Reed D, Kurfiss A, Breeze JL, Trinquart L, Davis JM
JAMA. 2023 Jul 11;330(2):161-169. doi: 10.1001/jama.2023.9350.
IMPORTANCE: Genomic testing in infancy guides medical decisions and can improve health outcomes. However, it is unclear whether genomic sequencing or a targeted neonatal gene-sequencing test provides comparable molecular diagnostic yields and times to return of results.
OBJECTIVE: To compare outcomes of genomic sequencing with those of a targeted neonatal gene-sequencing test.
DESIGN, SETTING, AND PARTICIPANTS: The Genomic Medicine for Ill Neonates and Infants (GEMINI) study was a prospective, comparative, multicenter study of 400 hospitalized infants younger than 1 year of age (proband) and their parents, when available, suspected of having a genetic disorder. The study was conducted at 6 US hospitals from June 2019 to November 2021.
EXPOSURE: Enrolled participants underwent simultaneous testing with genomic sequencing and a targeted neonatal gene-sequencing test. Each laboratory performed an independent interpretation of variants guided by knowledge of the patient’s phenotype and returned results to the clinical care team. Change in clinical management, therapies offered, and redirection of care was provided to families based on genetic findings from either platform.
MAIN OUTCOMES AND MEASURES: Primary end points were molecular diagnostic yield (participants with ≥1 pathogenic variant or variant of unknown significance), time to return of results, and clinical utility (changes in patient care).
RESULTS: A molecular diagnostic variant was identified in 51% of participants (n = 204; 297 variants identified with 134 being novel). Molecular diagnostic yield of genomic sequencing was 49% (95% CI, 44%-54%) vs 27% (95% CI, 23%-32%) with the targeted gene-sequencing test. Genomic sequencing did not report 19 variants found by the targeted neonatal gene-sequencing test; the targeted gene-sequencing test did not report 164 variants identified by genomic sequencing as diagnostic. Variants unidentified by the targeted genomic-sequencing test included structural variants longer than 1 kilobase (25.1%) and genes excluded from the test (24.6%) (McNemar odds ratio, 8.6 [95% CI, 5.4-14.7]). Variant interpretation by laboratories differed by 43%. Median time to return of results was 6.1 days for genomic sequencing and 4.2 days for the targeted genomic-sequencing test; for urgent cases (n = 107) the time was 3.3 days for genomic sequencing and 4.0 days for the targeted gene-sequencing test. Changes in clinical care affected 19% of participants, and 76% of clinicians viewed genomic testing as useful or very useful in clinical decision-making, irrespective of a diagnosis.
CONCLUSIONS AND RELEVANCE: The molecular diagnostic yield for genomic sequencing was higher than a targeted neonatal gene-sequencing test, but the time to return of routine results was slower. Interlaboratory variant interpretation contributes to differences in molecular diagnostic yield and may have important consequences for clinical management.
July 11, 2023
RPM for NICU and PICUrWGSrWGS Efficacy
Assessing Diversity in Newborn Genomic Sequencing Research Recruitment: Race/Ethnicity and Primary Spoken Language Variation in Eligibility, Enrollment, and Reasons for Declining
Cakici JA, Dimmock D, Caylor S, Gaughran M, Clarke C, Triplett C, Clark MM, Kingsmore SF, Bloss CS.
Clin Ther. 2023 Jul 8:S0149-2918(23)00220-5. doi: 10.1016/j.clinthera.2023.06.014. Online ahead of print.
PURPOSE: Diagnostic genomic research has the potential to directly benefit participants. This study sought to identify barriers to equitable enrollment of acutely ill newborns into a diagnostic genomic sequencing research study.
METHODS: We reviewed the 16-month recruitment process of a diagnostic genomic research study enrolling newborns admitted to the neonatal intensive care unit at a regional pediatric hospital that primarily serves English- and Spanish-speaking families. Differences in eligibility, enrollment, and reasons for not enrolling were examined as functions of race/ethnicity and primary spoken language.
FINDINGS: Of the 1248 newborns admitted to the neonatal intensive care unit, 46% (n = 580) were eligible, and 17% (n = 213) were enrolled. Of the 16 languages represented among the newborns’ families, 4 (25%) had translated consent documents. Speaking a language other than English or Spanish increased a newborn’s likelihood of being ineligible by 5.9 times (P < 0.001) after controlling for race/ethnicity. The main reason for ineligibility was documented as the clinical team declined having their patient recruited (41% [51 of 125]). This reason significantly affected families who spoke languages other than English or Spanish and was able to be remediated with training of the research staff. Stress (20% [18 of 90]) and the study intervention(s) (20% [18 of 90]) were the main reasons given for not enrolling.
IMPLICATIONS: This analysis of eligibility, enrollment, and reasons for not enrolling in a diagnostic genomic research study found that recruitment generally did not differ as a function of a newborn’s race/ethnicity. However, differences were observed depending on the parent’s primary spoken language. Regular monitoring and training can improve equitable enrollment into diagnostic genomic research. There are also opportunities at the federal level to improve access to those with limited English proficiency and thus decrease disparities in representation in research participation.
July 8, 2023
Newborn ScreeningRPM for NICU and PICU
Rapid Whole Genome Sequencing for Diagnosis of Single Locus Genetic Diseases in Critically Ill Children
Owen MJ, Batalov S, Ellsworth KA, Wright M, Breeding S, Hugh K, Kingsmore SF, Ding Y.
Methods Mol Biol. 2023;2621:217-239. doi: 10.1007/978-1-0716-2950-5_12.
Upon admission to intensive care units (ICU), the differential diagnosis of almost all infants with diseases of unclear etiology includes single locus genetic diseases. Rapid whole genome sequencing (rWGS), including sample preparation, short-read sequencing-by-synthesis, informatics pipelining, and semiautomated interpretation, can now identify nucleotide and structural variants associated with most genetic diseases with robust analytic and diagnostic performance in as little as 13.5 h. Early diagnosis of genetic diseases transforms medical and surgical management of infants in ICUs, minimizing both the duration of empiric treatment and the delay to start of specific treatment. Both positive and negative rWGS tests have clinical utility and can improve outcomes. Since first described 10 years ago, rWGS has evolved considerably. Here we describe our current methods for routine diagnostic testing for genetic diseases by rWGS in as little as 18 h.
April 12, 2023
RPM for NICU and PICUrWGS
Automated prioritization of sick newborns for whole genome sequencing using clinical natural language processing and machine learning
Peterson B, Hernandez EJ, Hobbs C, Malone Jenkins S, Moore B, Rosales E, Zoucha S, Sanford E, Bainbridge MN, Frise E, Oriol A, Brunelli L, Kingsmore SF, Yandell M.
Genome Med. 2023 Mar 16;15(1):18. doi: 10.1186/s13073-023-01166-7.
BACKGROUND: Rapidly and efficiently identifying critically ill infants for whole genome sequencing (WGS) is a costly and challenging task currently performed by scarce, highly trained experts and is a major bottleneck for application of WGS in the NICU. There is a dire need for automated means to prioritize patients for WGS.
METHODS: Institutional databases of electronic health records (EHRs) are logical starting points for identifying patients with undiagnosed Mendelian diseases. We have developed automated means to prioritize patients for rapid and whole genome sequencing (rWGS and WGS) directly from clinical notes. Our approach combines a clinical natural language processing (CNLP) workflow with a machine learning-based prioritization tool named Mendelian Phenotype Search Engine (MPSE).
RESULTS: MPSE accurately and robustly identified NICU patients selected for WGS by clinical experts from Rady Children’s Hospital in San Diego (AUC 0.86) and the University of Utah (AUC 0.85). In addition to effectively identifying patients for WGS, MPSE scores also strongly prioritize diagnostic cases over non-diagnostic cases, with projected diagnostic yields exceeding 50% throughout the first and second quartiles of score-ranked patients.
CONCLUSIONS: Our results indicate that an automated pipeline for selecting acutely ill infants in neonatal intensive care units (NICU) for WGS can meet or exceed diagnostic yields obtained through current selection procedures, which require time-consuming manual review of clinical notes and histories by specialized personnel.
March 16, 2023
RPM for NICU and PICUrWGS
Genomic sequencing has a high diagnostic yield in children with congenital anomalies of the heart and urinary system
Allred ET, Perens EA, Coufal NG, Sanford Kobayashi E, Kingsmore SF, Dimmock DP.
Front Pediatr. 2023 Mar 14;11:1157630. doi: 10.3389/fped.2023.1157630. eCollection 2023.
BACKGROUND: Congenital heart defects (CHD) and congenital anomalies of the kidney and urinary tract (CAKUT) account for significant morbidity and mortality in childhood. Dozens of monogenic causes of anomalies in each organ system have been identified. However, even though 30% of CHD patients also have a CAKUT and both organs arise from the lateral mesoderm, there is sparse overlap of the genes implicated in the congenital anomalies for these organ systems. We sought to determine whether patients with both CAKUT and CHD have a monogenic etiology, with the long-term goal of guiding future diagnostic work up and improving outcomes.
METHODS: Retrospective review of electronic medical records (EMR), identifying patients admitted to Rady Children’s Hospital between January 2015 and July 2020 with both CAKUT and CHD who underwent either whole exome sequencing (WES) or whole genome sequencing (WGS). Data collected included demographics, presenting phenotype, genetic results, and mother’s pregnancy history. WGS data was reanalyzed with a specific focus on the CAKUT and CHD phenotype. Genetic results were reviewed to identify causative, candidate, and novel genes for the CAKUT and CHD phenotype. Associated additional structural malformations were identified and categorized.
RESULTS: Thirty-two patients were identified. Eight patients had causative variants for the CAKUT/CHD phenotype, three patients had candidate variants, and three patients had potential novel variants. Five patients had variants in genes not associated with the CAKUT/CHD phenotype, and 13 patients had no variant identified. Of these, eight patients were identified as having possible alternative causes for their CHD/CAKUT phenotype. Eighty-eight percent of all CAKUT/CHD patients had at least one additional organ system with a structural malformation.
CONCLUSIONS: Overall, our study demonstrated a high rate of monogenic etiologies in hospitalized patients with both CHD and CAKUT, with a diagnostic rate of 44%. Thus, physicians should have a high suspicion for genetic disease in this population. Together, these data provide valuable information on how to approach acutely ill patients with CAKUT and CHD, including guiding diagnostic work up for associated phenotypes, as well as novel insights into the genetics of CAKUT and CHD overlap syndromes in hospitalized children.
March 14, 2023
RPM for NICU and PICU
Scalable, high quality, whole genome sequencing from archived, newborn, dried blood spots
Ding Y, Owen M, Le J, Batalov S, Chau K, Kwon YH, Van Der Kraan L, Bezares-Orin Z, Zhu Z, Veeraraghavan N, Nahas S, Bainbridge M, Gleeson J, Baer RJ, Bandoli G, Chambers C, Kingsmore SF.
NPJ Genom Med. 2023 Feb 14;8(1):5. doi: 10.1038/s41525-023-00349-w.
Universal newborn screening (NBS) is a highly successful public health intervention. Archived dried bloodspots (DBS) collected for NBS represent a rich resource for population genomic studies. To fully harness this resource in such studies, DBS must yield high-quality genomic DNA (gDNA) for whole genome sequencing (WGS). In this pilot study, we hypothesized that gDNA of sufficient quality and quantity for WGS could be extracted from archived DBS up to 20 years old without PCR (Polymerase Chain Reaction) amplification. We describe simple methods for gDNA extraction and WGS library preparation from several types of DBS. We tested these methods in DBS from 25 individuals who had previously undergone diagnostic, clinical WGS and 29 randomly selected DBS cards collected for NBS from the California State Biobank. While gDNA from DBS had significantly less yield than from EDTA blood from the same individuals, it was of sufficient quality and quantity for WGS without PCR. All samples DBS yielded WGS that met quality control metrics for high-confidence variant calling. Twenty-eight variants of various types that had been reported clinically in 19 samples were recapitulated in WGS from DBS. There were no significant effects of age or paper type on WGS quality. Archived DBS appear to be a suitable sample type for WGS in population genomic studies.
February 14, 2023
Newborn ScreeningRPM for NICU and PICUrWGS
25: A Multicenter Cohort Analysis of Rapid Genome Sequencing in the PICU
Rodriguez, Katherine; Kobayashi, Erica Sanford; VanDongen-Trimmer, Heather; Salz, Lisa; Foley, Jennifer; Whalen, Drewann; Oluchukwu, Okonkwo; Liu, Kuang Chuen; Burton, Jennifer; Syngal, Prachi; Kingsmore, Stephen; Coufal, Nicole.
Critical Care Medicine 51(1):p 13, January 2023.
Genetic disorders contribute significantly to morbidity and mortality in pediatric critical care. Diagnostic rapid whole genome sequencing (rWGS) has dramatically impacted care in neonatal intensive care units (ICU). There remains a population of undiagnosed patients with rare genetic diseases who present critically ill to the pediatric ICU (PICU) and the application of rWGS in this setting is not yet fully described. This study evaluated the clinical utility of rWGS in the PICU.
January 31, 2023
RPM for NICU and PICUrWGSrWGS Efficacy
Insights into the perinatal phenotype of Kabuki syndrome in infants identified by genome-wide sequencing
Wigby K, Hammer M, Tokita M, Patel P, Jones MC, Larson A, Bartolomei FV, Dykzeul N, Slavotinek A, Yip T, Bandres-Ciga S, Simpson BN, Suhrie K, Shankar S, Veith R, Bragg J, Powell C, Kingsmore SF, Dimmock D, Maron J, Davis J, Del Campo M.
Am J Med Genet A. 2023 Jan 18. doi: 10.1002/ajmg.a.63097. Online ahead of print.
Increasing use of unbiased genomic sequencing in critically ill infants can expand understanding of rare diseases such as Kabuki syndrome (KS). Infants diagnosed with KS through genome-wide sequencing performed during the initial hospitalization underwent retrospective review of medical records. Human phenotype ontology terms used in genomic analysis were aggregated and analyzed. Clinicians were surveyed regarding changes in management and other care changes. Fifteen infants met inclusion criteria. KS was not suspected prior to genomic sequencing. Variants were classified as Pathogenic (n = 10) or Likely Pathogenic (n = 5) by American College of Medical Genetics and Genomics Guidelines. Fourteen variants were de novo (KMT2D, n = 12, KDM6A, n = 2). One infant inherited a likely pathogenic variant in KMT2D from an affected father. Frequent findings involved cardiovascular (14/15) and renal (7/15) systems, with palatal defects also identified (6/15). Three infants had non-immune hydrops. No minor anomalies were universally documented; ear anomalies, micrognathia, redundant nuchal skin, and hypoplastic nails were common. Changes in management were reported in 14 infants. Early use of unbiased genome-wide sequencing enabled a molecular diagnosis prior to clinical recognition including infants with atypical or rarely reported features of KS while also expanding the phenotypic spectrum of this rare disorder.
January 18, 2023
Rare DiseaseRPM for NICU and PICU