Real-world utilization of guideline-directed genetic testing in inherited cardiovascular diseases.

Background: Cardiovascular disease continues to be the leading cause of death globally. Clinical practice guidelines aimed at improving disease management and positively impacting major cardiac adverse events recommend genetic testing for inherited cardiovascular conditions such as dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), long QT syndrome (LQTS), hereditary amyloidosis, and familial hypercholesterolemia (FH); however, little is known about how consistently practitioners order genetic testing for these conditions in routine clinical practice. This study aimed to assess the adoption of guideline-directed genetic testing for patients diagnosed with DCM, HCM, LQTS, hereditary amyloidosis, or FH. Methods: This retrospective cohort study captured real-world evidence of genetic testing from ICD-9-CM and ICD-10-CM codes, procedure codes, and structured text fields of de-identified patient records in the Veradigm Health Insights Ambulatory EHR Research Database linked with insurance claims data. Data analysis was conducted using an automated electronic health record analysis engine. Patient records in the Veradigm database were sourced from more than 250,000 clinicians serving over 170 million patients in outpatient primary care and specialty practice settings in the United States and linked insurance claims data from public and private insurance providers. The primary outcome measure was evidence of genetic testing within six months of condition diagnosis. Results: Between January 1, 2017, and December 31, 2021, 224,641 patients were newly diagnosed with DCM, HCM, LQTS, hereditary amyloidosis, or FH and included in this study. Substantial genetic testing care gaps were identified. Only a small percentage of patients newly diagnosed with DCM (827/101,919; 0.8%), HCM (253/15,507; 1.6%), LQTS (650/56,539; 1.2%), hereditary amyloidosis (62/1,026; 6.0%), or FH (718/49,650; 1.5%) received genetic testing. Conclusions: Genetic testing is underutilized across multiple inherited cardiovascular conditions. This real-world data analysis provides insights into the delivery of genomic healthcare in the United States and suggests genetic testing guidelines are rarely followed in practice.

Use of cell-free signals as biomarkers for early and easy prediction of preeclampsia.

Introduction: Preeclampsia (PE) is a leading cause of maternal and perinatal morbidity worldwide. However, current methods of screening are complicated and require special skill sets. In this observational study of prospectively collected samples, we wanted to evaluate if cell-free (cf) DNA could be an efficient biomarker for identification of at-risk patients. Methods: One hundred patients attending a private prenatal clinic in Canada were enrolled in their first trimester of pregnancy and a blood draw was carried out at 11 + 0 to 14 + 2 weeks' (timepoint A) and 17 + 6 to 25 + 5 weeks of gestation (timepoint B). CfDNA signals, namely concentration, fetal fraction, and fragment size distribution, were correlated with clinical outcomes in the test population to develop the logistic regression model. Results: Twelve patients developed PE-four early-stage and eight late-stage PE. Significant differences were observed between PE patients and control cases for all three cfDNA signals at timepoint A, while both fetal fraction and concentration were significantly different between PE patients and control cases at timepoint B. Overall, the model had a sensitivity of up to 100% and specificity of up to 87.5% at Timepoint A. Conclusion: This proof-of-principle study showed that use of this logistic regression model could identify patients at risk of preeclampsia in the first trimester of pregnancy.

Performance of a Paired-End Sequencing-Based Noninvasive Prenatal Screening Test in the Detection of Genome-Wide Fetal Chromosomal Anomalies.

BACKGROUND: Noninvasive prenatal tests (NIPTs) detect fetal chromosomal anomalies with high clinical sensitivity and specificity. We examined the performance of a paired-end sequencing-based NIPT in the detection of genome-wide fetal chromosomal anomalies including common trisomies, sex chromosomal aneuploidies (SCA), rare autosomal aneuploidies (RAAs), and partial deletions/duplications ≥7 Mb. METHODS: Frozen plasma samples from pregnant women were tested using the VeriSeq NIPT Solution v2 assay. All samples were previously tested with a laboratory-developed NIPT and had known clinical outcomes. Individuals performing the sequencing were blinded to clinical outcome data. Clinical sensitivity and specificity were determined for basic (chromosomes 21, 18, 13, X, and Y) and genome-wide screening modes. RESULTS: Of 2335 samples that underwent genome-wide analysis, 28 did not meet QC requirements, resulting in a first-pass assay failure rate of 1.2%. Basic screening analysis, excluding known mosaics, correctly classified 130/130 trisomy 21 samples (sensitivity >99.9%, 95% confidence interval [CI] 97.1%-100%), 41/41 trisomy 18 samples (sensitivity >99.9%, 95% CI 91.4%-100%), and 26/26 trisomy 13 samples (sensitivity >99.9%, 95% CI 87.1%-100%) with 6 false-positive results; specificities ≥99.90% were reported for all 3 trisomies. Concordance for SCAs ranged from 90.5%-100%. Genome-wide screening analysis including known mosaics correctly classified 27/28 RAAs and 20/27 partial deletions/duplications with a specificity of 99.80% for both anomalies, and an overall genome-wide specificity for all anomalies of 99.34%. CONCLUSIONS: The VeriSeq NIPT Solution v2 assay enables accurate identification of fetal aneuploidy, allowing detection of genome-wide fetal chromosomal anomalies with high clinical sensitivities and specificities and a low assay failure rate.Clinical Trial Notification [CTN] identification number [ID]: CT-2018-CTN-01585-1 v1, Protocol: NIPT T05 002.

Economic impact of using maternal plasma cell-free DNA testing to guide further workup in recurrent pregnancy loss.

OBJECTIVE: We have previously demonstrated that maternal-plasma cell-free DNA (cfDNA)-testing can detect chromosomal anomalies in recurrent pregnancy loss (RPL) with 81.8% sensitivity and 90.3% specificity. Here we assess whether this is cost effective in guiding further workup in RPLs. METHOD: A decision-analytic model was developed to compare the cost of various RPL management pathways: (1) current American Society for Reproductive Medicine (ASRM) RPL workup; (2) microarray or karyotyping analysis of products of conception (POCs) and RPL workup only for euploid cases; and (3) cfDNA testing and RPL workup only for euploid cases. Sample accessibility, failure rates, and sensitivity were specified for each test. Costs of sample collection, genetic tests, and RPL workup were considered. Analysis outcomes included detection rate of chromosomal anomaly and cost per patient tested. RESULTS: In comparison to existing cytogenetic testing on POCs, cfDNA testing pathway allowed for better sample accessibility with a lower cost per patient. In addition, using cfDNA to guide further workup significantly increases the number of causative fetal chromosome anomalies detected, reducing the number of patients undergoing unnecessary workup resulting in an overall cost savings. CONCLUSION: Our study showed that inclusion of cfDNA testing is a cost-effective approach to guide RPL workup.

Evaluation of an automated process for disclosure of negative noninvasive prenatal test results.

We designed and implemented a novel automated negative non-invasive prenatal test (NIPT) result disclosure process using a proprietary, HIPAA-compliant web-based portal. High-risk pregnant patients who opted for NIPT from 04/2017 to 12/2018 were given the option to receive their negative result through the automated process. Patients were required to watch a brief educational video and answer evaluative questions before downloading their result. After completing the process, patients completed a survey regarding their opinion of the efficiency and convenience of the process and their satisfaction. A total of 10,170 women registered online during the study period, and 8,965 completed the automated process (88%). Out of 8,965 women, 2,121 women responded to the survey (24%). Most (2,030 of 2,101) strongly agreed/agreed that they could easily navigate the patient portal (97%); 1,852 of 1,966 strongly agreed/agreed that disclosure was efficient and convenient (94%); 1,852 of 1,960 strongly agreed/agreed that they felt informed after watching a short educational video (94%); and 1,903 of 1,967 strongly agreed/agreed that they preferred downloading results rather than waiting for their next doctor's appointment (97%). This study demonstrates high patient satisfaction with this automated and scalable solution in a high-volume health system. As the utilization of genetic testing increases, we predict greater need for innovative healthcare delivery models.

Fetal aneuploidy screening with cell-free DNA in late gestation.

OBJECTIVE: The aim of this study was to evaluate clinical use of NIPT at gestational ages of 23 weeks and above. METHODS: A cohort of 5579 clinical patients with singleton gestations of 23 weeks or greater submitting a blood sample for NIPT in an 18-month period were selected for this study. Clinical outcomes were requested for samples with NIPT results indicating fetal aneuploidy and compared with NIPT findings to confirm concordance or discordance. RESULTS: A review of clinical indications revealed that a significantly (p < 0.0001) larger proportion of late-gestation samples indicated abnormal ultrasound findings with or without other indications, 6.2% and 42.1%, compared with early-gestation samples, 1.8% and 6.0%, respectively. Of 5372 reported late-gestation samples, 151 (2.8%) were reported as aneuploidy detected or suspected. In late-gestation samples, the overall observed positive predictive value (PPV) for NIPT was 64.7%, with an observed PPV of 100% in the subset of cases with multiple clinical indications including abnormal ultrasound findings. CONCLUSIONS: NIPT is a highly accurate prenatal screening option for women after 23 weeks of gestation. Women who presented for NIPT in the latter stages of pregnancy more frequently specified clinical indications of abnormal ultrasound findings than women who entered screening earlier in pregnancy.

Follow-up of multiple aneuploidies and single monosomies detected by noninvasive prenatal testing: implications for management and counseling.

OBJECTIVES: To determine the underlying biological basis for noninvasive prenatal testing (NIPT) results of multiple aneuploidies or autosomal monosomies. METHODS: Retrospective analysis of 113,415 tests to determine the study cohort, consisting of 138 (0.12%) cases reported as a single autosomal monosomy (n = 65), single trisomy with a sex chromosome aneuploidy (n = 36), or with multiple aneuploidies (n = 37). Clinical outcome information was reviewed and stratified into eight categories according to whether the karyotype or sonographic information agreed or disagreed with sequencing results. RESULTS: Of 67 cases with fetal or neonatal karyotypes available, 16 (24%) were partially or fully concordant with the NIPT result, 4 (6%) had aneuploidy on a reference chromosome, and 47 (70%) had normal fetal chromosomes, in which 5/47 had maternal malignancies reported. One case of maternal mosaic trisomy 8 was also detected. Of cases with no fetal karyotype information, ten had an abnormal clinical outcome, one was a normal live birth, and one reported maternal malignancy. CONCLUSIONS: Noninvasive prenatal test results of autosomal monosomy or multiple aneuploidies are rare but have a diversity of underlying biologic causes. Some reflect the fetal karyotype; some reflect the presence of other maternal or fetal chromosome abnormalities, and a small number are linked to maternal disease.

Noninvasive prenatal testing in the general obstetric population: clinical performance and counseling considerations in over 85 000 cases.

OBJECTIVE: The primary goal of this study was to provide clinically relevant information for appropriate patient counseling. METHOD: Demographics and test metrics were reviewed for 86 658 clinical cases. Outcome information was requested for samples reported as aneuploidy detected or suspected for chromosomes 21, 18, or 13; voluntary outcome reporting was encouraged for all discordant outcomes. RESULTS: Of 86 658 cases, 85 298 (98.4%) met inclusion criteria for result reporting. Of the 1360 (1.6%) cancellations, only 101 (0.1%) were for technical reasons. Average time to result was 3.3 business days. Aneuploidy was detected or suspected in 2142 (2.5%) samples. For aneuploidy detected cases with known clinical outcomes, the overall positive predictive value (PPV) was 83.5% (608/728); observed PPVs for trisomies 21, 18, and 13 ranged from 50.0 to 92.8%. As individual PPVs are determined by a patient's prior risk, we developed a chart for counseling patients on positive predictive value based on maternal age. CONCLUSION: This large-scale report reinforces that noninvasive prenatal testing is a highly accurate screen for fetal aneuploidy in the general obstetric population. Test improvements have facilitated a reduction in failure rates, time to result, and borderline results/unclassifiable results. We have developed a positive predictive value counseling tool to ensure appropriate patient education, counseling, and clinical utilization.

Noninvasive Prenatal Testing and Incidental Detection of Occult Maternal Malignancies.

IMPORTANCE: Understanding the relationship between aneuploidy detection on noninvasive prenatal testing (NIPT) and occult maternal malignancies may explain results that are discordant with the fetal karyotype and improve maternal clinical care. OBJECTIVE: To evaluate massively parallel sequencing data for patterns of copy-number variations that might prospectively identify occult maternal malignancies. DESIGN, SETTING, AND PARTICIPANTS: Case series identified from 125,426 samples submitted between February 15, 2012, and September 30, 2014, from asymptomatic pregnant women who underwent plasma cell-free DNA sequencing for clinical prenatal aneuploidy screening. Analyses were conducted in a clinical laboratory that performs DNA sequencing. Among the clinical samples, abnormal results were detected in 3757 (3%); these were reported to the ordering physician with recommendations for further evaluation. EXPOSURES: NIPT for fetal aneuploidy screening (chromosomes 13, 18, 21, X, and Y). MAIN OUTCOMES AND MEASURES: Detailed genome-wide bioinformatics analysis was performed on available sequencing data from 8 of 10 women with known cancers. Genome-wide copy-number changes in the original NIPT samples and in subsequent serial samples from individual patients when available are reported. Copy-number changes detected in NIPT sequencing data in the known cancer cases were compared with the types of aneuploidies detected in the overall cohort. RESULTS: From a cohort of 125,426 NIPT results, 3757 (3%) were positive for 1 or more aneuploidies involving chromosomes 13, 18, 21, X, or Y. From this set of 3757 samples, 10 cases of maternal cancer were identified. Detailed clinical and sequencing data were obtained in 8. Maternal cancers most frequently occurred with the rare NIPT finding of more than 1 aneuploidy detected (7 known cancers among 39 cases of multiple aneuploidies by NIPT, 18% [95% CI, 7.5%-33.5%]). All 8 cases that underwent further bioinformatics analysis showed unique patterns of nonspecific copy-number gains and losses across multiple chromosomes. In 1 case, blood was sampled after completion of treatment for colorectal cancer and the abnormal pattern was no longer evident. CONCLUSIONS AND RELEVANCE: In this preliminary study, a small number of cases of occult malignancy were subsequently diagnosed among pregnant women whose noninvasive prenatal testing results showed discordance with the fetal karyotype. The clinical importance of these findings will require further research.

Fetal sex chromosome testing by maternal plasma DNA sequencing: clinical laboratory experience and biology.

OBJECTIVE: To describe the clinical experience with noninvasive prenatal testing for fetal sex chromosomes using sequencing of maternal plasma cell-free DNA in a commercial laboratory. METHODS: A noninvasive prenatal testing laboratory data set was examined for samples in which fetal sex chromosomes were reported. Available clinical outcomes were reviewed. RESULTS: Of 18,161 samples with sex chromosome results, no sex chromosome aneuploidy was detected in 98.9% and the fetal sex was reported as XY (9,236) or XX (8,721). In 4 of 32 cases in which the fetal sex was reportedly discordant between noninvasive prenatal testing and karyotype or ultrasonogram, a potential biological reason for the discordance exists, including two cases of documented co-twin demise, one case of a maternal kidney transplant from a male donor, and one case of fetal ambiguous genitalia. In the remaining 204 samples (1.1%), one of four sex chromosome aneuploidies (monosomy X, XXX, XXY, or XYY) was detected. The frequency of false positive results for sex chromosome aneuploidies is a minimum of 0.26% and a maximum of 1.05%. All but one of the discordant sex chromosome aneuploidy results involved the X chromosome. In two putative false-positive XXX cases, maternal XXX was confirmed by karyotype. For the false-positive cases, mean maternal age was significantly higher in monosomy X (P<.001) and lower in XXX (P=.008). CONCLUSION: Noninvasive prenatal testing results for sex chromosome aneuploidy can be confounded by maternal or fetal biological phenomena. When a discordant noninvasive prenatal testing result is encountered, resolution requires additional maternal history, detailed fetal ultrasonography, and determination of fetal and possibly maternal karyotypes.

Non-invasive Prenatal Testing: Technologies, Clinical Assays and Implementation Strategies for Women's Healthcare Practitioners.

The field of prenatal genetic testing has exploded with new non-invasive technologies and test options in the past several years. It is challenging for women's healthcare providers to keep up with the multitude of publications and provide patients with the most accurate and up-to-date information possible regarding prenatal testing. In this article, we examine the sequencing technologies that provide the framework for non-invasive prenatal testing (NIPT) and review the major North American NIPT clinical validation studies published in 2011 and 2012. This paper also compares and contrasts the commercially available non-invasive prenatal tests in the United States, discusses clinical implementation recommendations from professional societies and highlights considerations for genetic counseling.

Initial clinical laboratory experience in noninvasive prenatal testing for fetal aneuploidy from maternal plasma DNA samples.

OBJECTIVE: The aim of this study is to report the experience of noninvasive prenatal DNA testing using massively parallel sequencing in an accredited clinical laboratory. METHODS: Laboratory information was examined for blood samples received for testing between February and November 2012 for chromosome 21 (Chr21), Chr18, and Chr13. Monosomy X (MX) testing was available from July 2012 for cystic hygroma indication. Outcomes were collected from providers on samples with positive results. RESULTS: There were 5974 samples tested, and results were issued within an average of 5.1 business days. Aneuploidy was detected in 284 (4.8%) samples (155 Chr21, 66 Chr18, 19 Chr13, 40 MX, and four double aneuploidy). Follow-ups are available for 245/284 (86%), and 77/284 (27.1%) are confirmed, including one double-aneuploidy case concordant with cytogenetics from maternal malignancy. Fourteen (0.2%) discordant (putative false-positive) results (one Chr21, six Chr18, three Chr13, three MX, and one Chr21/13) have been identified. Five (0.08%) false-negative cases are reported (two trisomy 21, two trisomy 18, and one MX). In 170 (2.8%) cases, the result for a single chromosome was indefinite. CONCLUSIONS: This report suggests that clinical testing of maternal cell-free DNA for fetal aneuploidy operates within performance parameters established in validation studies. Noninvasive prenatal testing is sensitive to biological contributions from placental and maternal sources.

Trends in prenatal screening and diagnostic testing among women referred for advanced maternal age.

OBJECTIVE: We evaluated the trends in uptake of amniocentesis and chorionic villi sampling (CVS) for prenatal diagnosis compared with uptake of first and second trimester prenatal serum screening for Down syndrome among patients referred for genetic counseling for advanced maternal age (AMA). METHODS: Patients referred for AMA genetic counseling from 2001 through 2008 were informed of both prenatal serum screening and invasive diagnostic testing options. Testing offered and testing decisions were entered in a computer database and uptake rates calculated for each year with trends compared using logistic regression analysis. RESULTS: From 2001 through 2007, we observed a decline in amniocentesis and CVS uptake (p = 0.0001). This trend reversed in 2008 for both invasive procedures (p = 0.0001). Uptake of prenatal serum screening increased over the study period with uptake of first trimester screening increasing 1.7 fold in 2008. CONCLUSION: Improved prenatal screening tests and increased availability of screening for AMA patients has led to a steady decline in uptake of invasive testing from 2001 through 2007. This trend reversed from 2007 through 2008. Possible reasons for this reversal are discussed.

Supernumerary marker chromosomes detected in 100,000 prenatal diagnoses: molecular cytogenetic studies and clinical significance.

OBJECTIVE: To evaluate the clinical significance of the supernumerary marker chromosomes (SMCs) detected during prenatal diagnosis. METHODS: We retrospectively studied cytogenetic/fluorescence in situ hybridization (FISH) results and clinical evaluation of 110 marker cases identified from approximately 100,000 cases referred for prenatal diagnosis. The clinical follow-up performed was focused on cases with de novo markers not derived from chromosome 15. RESULTS: Among the 110 SMCs, 79 (71.8%) were de novo, 24 (21.8%) were familial, and the origin was undetermined in 7 cases. Fifty-eight of the SMCs originated from nonacrocentric chromosomes and 52 SMCs were derived from acrocentric chromosomes, with 27 originating from chromosome 15. Twenty-two of the SMCs from chromosome 15 did not contain the Prader-Willi/Angelman syndrome critical region, and uniparental disomy was ruled out in 19/19 cases. Clinical information ranging from birth to 4 years was obtained for 46 de novo cases with nonchromosome-15-derived SMCs. Of these cases, 11/11 acrocentric SMCs resulted in normal phenotype. In contrast, 4/23 cases with single nonacrocentric SMCs and 3/5 cases with two or more SMCs resulted in an abnormal phenotype. CONCLUSIONS: Our data suggests an overall low risk for acrocentric SMCs and a higher risk for nonacrocentric SMCs. Phenotypes associated with markers derived from some specific chromosomes are also discussed.

Residual risk for cytogenetic abnormalities after prenatal diagnosis by interphase fluorescence in situ hybridization (FISH).

Results from conventional cytogenetic studies on 21 609 amniotic fluid specimens were analyzed retrospectively to determine the residual risk for a cytogenetic abnormality if interphase FISH, capable of only detecting aneuploidy for chromosomes 13, 18, 21, X and Y, was performed and did not reveal an abnormality. Detection rates (the probability of detecting a cytogenetic abnormality when an abnormality is present) and residual risks (the likelihood of a cytogenetic abnormality, in view of normal interphase FISH results) were calculated for the four major clinical indications for prenatal diagnosis (advanced maternal age, abnormal maternal serum screen indicating increased risk for trisomy 18 or trisomy 21, abnormal maternal serum screen indicating increased risk for neural tube defects and ultrasound abnormality). Differences in detection rates were observed to depend on clinical indication and presence or absence of ultrasound abnormalities. The detection rate ranged from 18.2 to 82.6% depending on the clinical indication. The detection rates of abnormalities significant to the pregnancy being evaluated (i.e. abnormalities excluding familial balanced rearrangements and familial markers) were between 28.6 and 86.4%. The presence of ultrasound abnormalities increased the detection rate from 72.2 to 92.5% for advanced maternal age and from 78.6 to 91.3% for abnormal maternal serum screen, indicating increased risk for trisomy 18 or trisomy 21. With regard to residual risk, the risk for a clinically significant abnormality decreased from 0.9-10.1%, prior to the interphase FISH assay, to a residual risk of 0.6-1.5% following a normal interphase FISH result in the 4 groups studied. Providing patients with detection rates and residual risks, most relevant to their situation (clinical indication and presence or absence of ultrasound abnormality) during counseling, could help them better understand the advantages and limitations of interphase FISH in their prenatal diagnostic evaluation.

Prenatal diagnosis of 45,X and 45,X mosaicism: the need for thorough cytogenetic and clinical evaluations.

OBJECTIVES: Mosaicism involving a 45,X cell line is relatively common in prenatal diagnosis. In prenatally diagnosed cases, the prognosis of non-mosaic 45,X and 45,X/46,XY mosaicism are different. Therefore, accurate identification of a cell line containing Y chromosome is critical for genetic counseling and postnatal management. METHODS: We investigated the ultrasound findings and outcomes of pregnancies with a 45,X cell line identified during mid-trimester cytogenetic analysis. RESULTS: A total of 105 cases were found to have a 45,X cell line by standard cytogenetic analysis. Seventy-four cases were found to have non-mosaic 45,X at initial diagnosis. Of these 74 cases, 68 had abnormal ultrasound findings that were characteristic of Turner syndrome. Of the six cases with normal ultrasound findings, ultrasound examination was normal with male genitalia identified in three cases. Thorough cytogenetic and fluorescent in situ hybridization (FISH) analysis identified Y chromosome material in all three cases, one with a dicentric Y;14 chromosome and the other two cases with a marker chromosome containing Sex-determining Region (SRY) material in a small portion of the cells. In contrast, in 31 cases with a mosaic 45,X karyotype, ultrasound abnormality was identified only in one case. CONCLUSIONS: The present data suggest the need for follow-up ultrasound examination and thorough cytogenetic and molecular analysis for Y chromosome material in 45,X cases with normal ultrasound findings.