Barriers to completion of expanded carrier screening in an inner city population.

PURPOSE: The American College of Medical Genetics and Genomics emphasizes a "consistent and equitable approach for offering carrier screening." At our academic center, publicly insured prenatal patients underwent universal expanded carrier screening (ECS) to promote equitable care. The aim of the study was to evaluate rates, time, and barriers to complete ECS. This was defined as post-test counseling and partner testing after a patient was found heterozygous for a pathogenic variant. METHODS: In this descriptive retrospective cohort study from 2018 to 2021, patients were offered ECS, consisting of 283 recessive and X-linked genes. Heterozygotes were contacted by genetic counselors (≤5 attempts) for education and partner testing. Rates of counseling, partner testing, diagnostic procedures, follow-up times, and barriers to completion were assessed. RESULTS: During this time, 643 women underwent ECS. Of these 643 women, 462 were heterozygotes and 326 of 462 had undergone counseling. Two hundred twenty-two of 462 partners obtained testing, with a median of 32 days from patient to partner result. Approximately 21 couples were heterozygous for the same pathogenic variant. One patient pursued diagnostic testing. CONCLUSION: ECS offers useful information; however, this study highlights significant barriers to completion. There was suboptimal patient follow-up and low partner screening, perhaps from insufficient time to educate and counsel. Future directions include implementing quality measures to ensure optimal completion.

Opening Pandora's box: abnormal genetic carrier screening and need for lifetime follow-up.

OBJECTIVE: Expanded carrier screening (ECS) is rising in popularity because of its application in a diverse population, its decreasing cost, and efficiency.1 However, it has traditionally been used to assess fetal risk. The next generation sequencing ECS panel offered at our academic medical center consists of 283 genes associated with hereditary disorders. Of those, 20 (7.1%) are autosomal recessive conditions, notable for variable expression of the clinical phenotype in heterozygous carriers, which may increase maternal risk for malignancy, bleeding, cardiovascular, or rheumatologic disease. Another 21 (7.4%) are X-linked conditions. We aimed to evaluate the prevalence of variants that have a potential for maternal phenotypic expression and whether identification of specific variants prompted patients to pursue further care in our health system, namely comprehensive genetic counseling and further healthcare consults when recommended. STUDY DESIGN: An institutional review board-approved descriptive retrospective cohort study was performed in a New York City academic medical center at which reproductive aged women were offered universal ECS from 2018 to 2021 by their provider, inclusive of obstetrician-gynecologists, maternal-fetal medicine physicians, and genetic counselors. Pretest counseling was performed by the ordering provider. Patients found to carry mutations with the potential for maternal phenotypic expression were contacted by genetic counselors regarding their clinical risks. In addition, patients who were carriers for factor XI deficiency, Bernard Soulier syndrome, ataxia telangectesia, fumarase deficiency, Nijmegen breakage syndrome, Duchenne muscular dystrophy, and familial hypercholesterolemia were advised to seek specialized healthcare pertaining to their clinical risk. The genetic counseling summary was placed in the electronic medical records (EMRs) so that the primary provider could view the findings. Through our EMRs, we evaluated the rates of healthcare uptake among these patients for at least 1 year after delivery. RESULTS: In total, 168 of 1184 (14.2%) patients were identified as carriers of mutations with a potential for maternal phenotypic expression. Of these, 156 (93%) were pregnant and 12 (7%) were preconception. Of those patients, 143 (85%) were carriers of autosomal recessive traits (Figure 1), whereas 22 of 168 (13%) patients were carriers of X-linked conditions (Figure 2) and 3 of 168 (2%) patients carried both autosomal recessive traits and X-linked conditions. Of these carriers, 132 of 168 (78.6%) patients underwent genetic counseling. The most common heterozygous mutations were sickle cell trait (25.6%), thalassemia (alpha and/or beta) trait (14.2%), factor XI deficiency (4.7%), dystrophic epidermolysis bullosa (4.2%), and Alport syndrome (4.1%). Two patients were diagnosed as homozygous carriers of nonclassical congenital adrenal hyperplasia. During the study period, 23 of 168 (13.6%) patients were heterozygous for specific pathogenic variants (inclusive of factor XI, Bernard Soulier syndrome, ataxia telangectesia, fumarase deficiency, Nijmegen breakage syndrome, Duchenne muscular dystrophy, and familial hypercholesterolemia) and were advised to seek specialized healthcare pertaining to these findings. Of these, 20 (87.0%) received genetic counseling with standardized recommendations, however, only 4 of 23 (17%) patients pursued the recommended referrals during our study period. CONCLUSION: This study described the follow-up rates among patients identified as carriers of conditions with the potential for maternal phenotypic expression using ECS. We observed that 14.2% of patients who underwent ECS were identified as carriers of genetic mutations with the potential for maternal phenotypic expression, and of the 23 who were recommended specific care because a pathogenic variant was identified, only 17.4% of patients followed the recommendations. We believe that as ECS implementation becomes widespread, more maternal carriers with clinical risk to themselves will be identified. Therefore, as we open this Pandora's box, the burden of counseling and follow-up must be addressed.

The role of the first trimester screen in the face of normal cell free DNA.

OBJECTIVE: There is no consensus for the method of aneuploidy screening in pregnancy. Cell free DNA (cfDNA) is the most sensitive screen for trisomies 21, 13, and 18, however the first trimester screen (FTS) is a marker for other adverse outcomes, such as structural anomalies, growth restriction, and preeclampsia. In 2019, we offered FTS (nuchal translucency (NT) and analytes) with or without cfDNA. The purpose of this study was to assess clinical relevance of abnormal FTS in women with normal cfDNA. METHODS: We retrospectively reviewed women undergoing screening in our Fetal Evaluation Unit in 2019. Women included had normal cfDNA and abnormal FTS; consisting of NT >95%, PAPP-A < 0.4 MoM, beta-HCG >2.5 MoM, or overall increased risk of trisomies. RESULTS: 195 patients had abnormal FTS and normal cfDNA. 41 (21%) had adverse maternal outcomes including hypertension, abnormal placentation, and placental abruption. 34 (17%) had adverse fetal outcomes including growth restriction, structural anomalies, fetal demise, polyhydramnios, previable PPROM, necrotizing enterocolitis after a preterm birth, and a balanced translocation. CONCLUSION: Abnormal FTS predicts adverse outcomes in 33% of women with normal cfDNA. Our data suggests that offering universal FTS with cfDNA may have clinical benefit.