Preimplantation genetic testing for monogenic disorders: clinical experience with BRCA1 and BRCA2 from 2010-2021.

PURPOSE: Our aim was to describe the reproductive decisions and outcomes of BRCA-positive patients who used preimplantation genetic testing for monogenic disorders (PGT-M). METHODS: We performed a retrospective case series of all PGT-M cycles for BRCA variants between 2010-2021 at a large urban academic fertility center. All patients who underwent ≥ 1 cycle of IVF with PGT-M for BRCA1 or BRCA2 were included. The primary outcome was total number of BRCA-negative euploid embryos per patient. RESULTS: Sixty four patients underwent PGT-M for BRCA variants. Forty-five percent (29/64) were BRCA1-positive females, 27% (17/64) were BRCA2-positive females, 16% (10/64) were BRCA1-positive males, 11% (7/64) were BRCA2-positive males, and one was a BRCA1 and BRCA2-positive male. There were 125 retrieval cycles with PGT-M, and all cycles included PGT for aneuploidy (PGT-A). Eighty-six percent (55/64) of patients obtained at least one BRCA- negative euploid embryo, with median of 1 (range 0-10) BRCA-negative euploid embryo resulted per cycle and median 3 (range 0-10) BRCA-negative euploid embryos accumulated per patient after a median of 2 (range 1-7) oocyte retrievals. Sixty-four percent (41/64) of patients attempted at least one frozen embryo transfer (FET) with a total of 68 FET cycles. Fifty-nine percent (40/68) of embryos transferred resulted in live births. Subgroup analysis revealed different reproductive pathways for BRCA1-positive females, BRCA2-positive females, and BRCA1/2-positive males (p < 0.05). CONCLUSION: PGT-M is a viable option for BRCA-positive patients to avoid transmission while building their families. Most patients in our cohort achieved pregnancy with BRCA-negative euploid embryos.

Chromosomal, gestational, and neonatal outcomes of embryos classified as a mosaic by preimplantation genetic testing for aneuploidy.

OBJECTIVE: To understand the clinical risks associated with the transfer of embryos classified as a mosaic using preimplantation genetic testing for aneuploidy. DESIGN: Analysis of data collected between 2017 and 2023. SETTING: Multicenter. PATIENTS: Patients of infertility treatment. INTERVENTION: Comparison of pregnancies resulting from embryos classified as euploid or mosaic using the 20%-80% interval in chromosomal intermediate copy numbers to define a mosaic result. MAIN OUTCOME MEASURES: Rates of spontaneous abortion, birth weight, length of gestation, incidence of birth defects, and chromosomal status during gestation. RESULTS: Implanted euploid embryos had a significantly lower risk of spontaneous abortion compared with mosaic embryos (8.9% [n = 8,672; 95% confidence interval {CI95} 8.3, 9.5] vs. 22.2% [n = 914; CI95 19.6, 25.0]). Embryos with mosaicism affecting whole chromosomes (not segmental) had the highest risk of spontaneous abortion (27.6% [n = 395; CI95 23.2, 32.3]). Infants born from euploid, mosaic, and whole chromosome mosaic embryos had average birth weights and lengths of gestation that were not statistically different (3,118 g and 267 days [n = 488; CI95 3,067, 3,169, and 266, 268], 3052 g and 265 days [n = 488; CI95 2,993, 3,112, and 264,267], 3,159 g and 268 days [n = 194; CI95 3,070, 3,249, and 266,270], respectively). Out of 488 infants from mosaic embryo transfers (ETs), one had overt gross abnormalities as defined by the Centers for Disease Control and Prevention. Most prenatal tests performed on pregnancies from mosaic ETs had normal results, and only three pregnancies produced prenatal test results reflecting the mosaicism detected at the embryonic stage (3 out of 250, 1.2%; CI95 0.25, 3.5). CONCLUSION: Although embryos classified as mosaic experience higher rates of miscarriage than euploid embryos (with a particularly high frequency shortly after implantation), infants born of mosaic ETs are similar to infants of euploid ETs. Prenatal testing indicates that mosaicism resolves during most pregnancies, although this process is not perfectly efficient. In a small percentage of cases, the mosaicism persists through gestation. These findings can serve as risk-benefit considerations for mosaic ETs in the fertility clinic.

Blinded rebiopsy and analysis of noneuploid embryos with 2 distinct preimplantation genetic testing platforms for aneuploidy.

OBJECTIVE: To determine how often a noneuploid result from a single trophectoderm (TE) biopsy tested with the next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidy (PGT-A) is concordant with rebiopsies tested with a single-nucleotide polymorphism (SNP) array-based PGT-A platform. DESIGN: Blinded prospective cohort study. SETTING: University-affiliated fertility center. PATIENT(S): One hundred blastocysts were chosen from donated samples; on TE biopsy with NGS-based PGT-A, 40 had at least one whole chromosome full copy number aneuploidy alone, 20 had a single whole chromosome intermediate copy number ("whole chromosome mosaic"), 20 had a single full segmental aneuploidy (segA), and 20 had a single segmental intermediate copy number ("segmental mosaic"). INTERVENTIONS: Four rebiopsies were collected from each embryo: 3 TE biopsies and the remaining embryo. Each rebiopsy was randomized, blinded, and assessed with an SNP array-based PGT-A platform that combines copy number and allele ratio analyses, without mosaicism reporting. MAIN OUTCOME MEASURE(S): Concordance between the NGS result and rebiopsy results and within each embryo's blinded rebiopsy results. RESULT(S): Next-generation sequencing-diagnosed whole chromosome aneuploidy (WCA) was reconfirmed in 95% (95% confidence interval [CI], 83%-99%) of embryos; 2 embryos with NGS-diagnosed WCA were called euploid on all conclusive rebiopsies. Among embryos with NGS-diagnosed whole chromosome mosaicism, 35% (95% CI, 15%-59%) were called euploid and 15% (95% CI, 3%-38%) were called whole chromosome aneuploid on all conclusive rebiopsies. A total of 30% (95% CI, 12%-54%) of embryos with NGS-diagnosed segA and 65% (95% CI, 41%-85%) of embryos with NGS-diagnosed segmental mosaicism were called euploid on all conclusive rebiopsies. In total, 13% (95% CI, 6%-25%) of embryos with NGS-diagnosed full copy number aneuploidy and 50% (95% CI, 34%-66%) of embryos with NGS-diagnosed mosaicism had uniformly euploid SNP results. Conversely, all embryos with at least one noneuploid SNP result (n = 72) either had SNP-diagnosed aneuploidy on another rebiopsy from the same embryo or NGS-diagnosed aneuploidy/mosaicism involving the same chromosome. CONCLUSION(S): Next-generation sequencing-diagnosed WCA is highly concordant with rebiopsies tested with an SNP array-based PGT-A; however, whole chromosome mosaicism, segA, and segmental mosaicism are less concordant, reinforcing that embryos with these results may have reproductive potential and be suitable for transfer.

Evidence-based management of preimplantation chromosomal mosaicism: lessons from the clinic.

Mosaic results obtained through preimplantation genetic testing for aneuploidy pose ongoing challenges to clinical practice. Thorough genetic counseling for patients considering mosaic embryo transfer is consistently recommended by many best-practice statements, and providers are charged with the task of assessing and explaining potential prenatal, neonatal, and long-term risks. However, an increasing amount of outcome data from transferred embryos with mosaic results do not show any evidence of increased risk to ongoing pregnancies or newborns. This article examines how to reconcile these data with the current practices for patient education about preimplantation genetic testing for aneuploidy and mosaic embryo risk assessment, through an evidence-based lens.

Using outcome data from one thousand mosaic embryo transfers to formulate an embryo ranking system for clinical use.

OBJECTIVE: To study how the attributes of mosaicism identified during preimplantation genetic testing for aneuploidy relate to clinical outcomes, in order to formulate a ranking system of mosaic embryos for intrauterine transfer. DESIGN: Compiled analysis. SETTING: Multi-center. PATIENT(S): A total of 5,561 euploid blastocysts and 1,000 mosaic blastocysts used in clinical transfers in patients undergoing fertility treatment. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Implantation (gestational sac), ongoing pregnancy, birth, and spontaneous abortion (miscarriage before 20 weeks of gestation). RESULT(S): The euploid group had significantly more favorable rates of implantation and ongoing pregnancy/birth (OP/B) compared with the combined mosaic group or the mosaic group affecting only whole chromosomes (implantation: 57.2% vs. 46.5% vs. 41.8%; OP/B: 52.3% vs. 37.0% vs. 31.3%), as well as lower likelihood of spontaneous abortion (8.6% vs. 20.4% vs. 25%). Whole-chromosome mosaic embryos with level (percent aneuploid cells) <50% had significantly more favorable outcomes than the ≥50% group (implantation: 44.5% vs. 30.4%; OP/B: 36.1% vs. 19.3%). Mosaic type (nature of the aneuploidy implicated in mosaicism) affected outcomes, with a significant correlation between number of affected chromosomes and unfavorable outcomes. This ranged from mosaicism involving segmental abnormalities to complex aneuploidies affecting three or more chromosomes (implantation: 51.6% vs. 30.4%; OP/B: 43.1% vs. 20.8%). Combining mosaic level, type, and embryo morphology revealed the order of subcategories regarding likelihood of positive outcome. CONCLUSION(S): This compiled analysis revealed traits of mosaicism identified with preimplantation genetic testing for aneuploidy that affected outcomes in a statistically significant manner, enabling the formulation of an evidence-based prioritization scheme for mosaic embryos in the clinic.

Clinical error rates of next generation sequencing and array comparative genomic hybridization with single thawed euploid embryo transfer.

We investigated clinical error rates with single thawed euploid embryo transfer (STEET) diagnosed by next generation sequencing (NGS) and array comparative genomic hybridization (aCGH). A total of 1997 STEET cycles after IVF with preimplantation genetic testing for aneuploidy (PGT-A) from 2010 to 2017 were identified; 1151 STEET cycles utilized NGS, and 846 STEET cycles utilized aCGH. Any abortions, spontaneous or elective, in which products of conception (POCs) were collected were reviewed. Discrepancies between chorionic villus sampling, amniocentesis, or live birth results and PGT-A diagnosis were also included. Primary outcomes were clinical error rate per: ET, pregnancy with gestational sac, live birth, and spontaneous abortion with POCs available for analysis. Secondary outcomes included implantation rate (IR), spontaneous abortion rate (SABR), and ongoing pregnancy/live birth rate (OPR/LBR). The clinical error rates in the NGS cohort were: 0.7% per embryo, 1% per pregnancy with gestational sac, and 0.1% rate per OP/LB. The error rate per SAB with POCs was 13.3%. The IR was 69.1%, the OPR/LBR was 61.6%, and the spontaneous abortion rate was 10.2%. The clinical error rates in the aCGH cohort were: 1.3% per embryo, 2% per pregnancy with gestational sac, and 0.4% rate per OP/LB. The error rate per SAB with POCs was 23.3%. The IR was 63.8%, the OPR/LBR was 54.6%, and the SAB rate was 12.4%. Our findings demonstrate that, although NGS and aCGH are sensitive platforms for PGT-A, errors still occur. Appropriate patient counseling and routine prenatal screening are recommended for all patients undergoing IVF/PGT-A.

Experiences and psychological outcomes of the oocyte donor: a survey of donors post-donation from one center.

PURPOSE: To assess the experiences and psychological outcomes of oocyte donors from one fertility center. METHODS: An anonymous survey was distributed via a secure email to 161 donors who underwent oocyte donation-anonymous, directed/known, and recruited agency-between January 2008 and January 2019 at the NYU Langone Fertility Center. RESULTS: Thirty-six donors completed the survey with the majority between 2 and 10 years since donation. Respondents reported a high prevalence of psychiatric symptoms or diagnoses post-donation. The majority of donors reported positive thoughts and feelings toward their donation process as well as to the knowledge of children born from their donation. Negative comments about donation were in the minority but focused on unexpected aspects about the process or outcome. Based on qualitative analysis, thoughts about family or "family-oriented thoughts" were the most frequent theme in respondent comments. 62.5% of respondents reporting that they would be open to identity-disclosure or open donation after experiencing the process. CONCLUSIONS: Despite a high reported prevalence of psychiatric symptoms, the majority of respondents felt positively about the donation experience as well as the prospect of open donation or identity-disclosure post-donation. Further research on long-term psychological outcomes, related to all aspects of donation, is important as the counseling and informed consent of oocyte donors continues to evolve. These data will be particularly important with regard to the aspect of disclosure, both planned and unplanned, in the modern era of electronic information sharing.

Transfer of embryos with positive results following preimplantation genetic testing for monogenic disorders (PGT-M): experience of two high-volume fertility clinics.

PURPOSE: To assess the experiences of two large fertility clinics in which embryos with positive results following preimplantation genetic testing for monogenic disorders (PGT-M) were transferred upon patient request, in order to explore the nature of the conditions for which these requests have been made and review ethical considerations. METHODS: Retrospective review of previous embryo transfers at the NYU Langone Fertility Center and ORM Fertility was performed. Embryo transfers prior to May 2019 in which embryo biopsy and PGT-M occurred were reviewed, and transferred embryos that were positive for a monogenic disorder (excluding autosomal recessive carriers) were identified. RESULTS: Seventeen patients were identified who elected to transfer 23 embryos that tested positive for nine different monogenic disorders. Most of the embryos transferred were positive for disorders that are autosomal dominant (15/23), are adult-onset (14/23), are associated with reduced penetrance (16/23), and have available management to lessen symptom severity (22/23). Transfer of positive embryos most commonly occurred for hereditary cancer susceptibility syndromes (9/23 embryos), particularly hereditary breast and ovarian cancer syndrome. CONCLUSIONS: When unaffected embryos are not produced following in vitro fertilization with PGT-M, some patients request to transfer embryos with positive test results. The majority of transfers were for embryos positive for adult-onset, reduced penetrance diseases. As these requests will likely increase over time, it is essential to consider the practical and ethical implications.

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.

What are patients doing with their mosaic embryos? Decision making after genetic counseling.

OBJECTIVE: To assess patient decisions regarding mosaic embryos and their impact on clinical outcomes. DESIGN: Review of patients who had genetic counseling regarding mosaic embryos. SETTING: Academic department. PATIENT(S): Ninety-eight patients who had mosaic embryos but no euploid embryos. INTERVENTION(S): Genetic counseling to discuss mosaic-embryo transfer (MET) after preimplantation genetic testing for aneuploidy. MAIN OUTCOME MEASURE(S): Patient decisions regarding MET. Outcomes for patients who pursued MET were compared with those for patients who pursued additional in vitro fertilization or intrauterine insemination cycles. Decisions regarding prenatal testing after MET were assessed. RESULT(S): Initially, 29.6% of patients pursued MET and 41.8% attempted a new treatment cycle. Only 6.1% of patients discarded their mosaic embryos without further treatment. Of the remaining patients, 2.0% transported their mosaic embryos to a different facility and 20.5% had not taken further action while their embryos remain stored. Patients who pursued additional cycles were more likely to have an ongoing pregnancy compared with those who pursued MET (51.2% vs. 27.6%; P<.05); however, there was no statistically significant difference in the percentage of patients who had at least one biochemical pregnancy or spontaneous abortion. Ultimately, 32.7% of patients underwent MET, and 54.5% of pregnant patients pursued amniocentesis. CONCLUSION(S): MET is desired by a substantial proportion of patients who do not have euploid embryos. Patients who opt for additional treatment cycles have a greater chance of achieving an ongoing pregnancy compared with those who pursue MET; however, future studies are needed to compare the cost-effectiveness for both options.

Counselling considerations for chromosomal mosaicism detected by preimplantation genetic screening.

The evolution of preimplantation genetic screening (PGS) for aneuploidy to blastocyst biopsy and more sensitive 24-chromosome screening techniques has resulted in a new diagnostic category of PGS results: those classified as mosaic. This diagnosis presents significant challenges for clinicians in developing policies regarding transfer and storage of such embryos, as well as in providing genetic counselling for patients prior to and following PGS. Given the high frequency of mosaic PGS results and the wide range of possible associated outcomes, there is an urgent need to understand how to appropriately counsel patients regarding such embryos. This is the first commentary to thoroughly address pre- and post-test genetic counselling recommendations, as well as considerations regarding prenatal screening and diagnosis. Current data on mosaic PGS results are summarized along with embryo selection considerations and potential outcomes of embryos diagnosed as mosaic.

Diagnosis and clinical management of embryonic mosaicism.

Embryonic mosaicism occurs when two or more cell populations with different genotypes are present within the same embryo. New diagnostic techniques for preimplantation genetic screening (PGS), such as next-generation sequencing, have led to increased reporting of mosaicism. The interpretation of mosaicism is complicated because the transfer of some mosaic embryos has resulted in live births. Mosaic embryos may represent a third category between normal (euploidy) and abnormal (aneuploidy). This category of mosaic embryos may be characterized by decreased implantation and pregnancy potential as well as increased risk of genetic abnormalities and adverse pregnancy outcomes. Euploid embryos should be preferentially transferred over mosaic embryos. Genetic counseling is necessary before the transfer of a mosaic embryo is considered. Certain types of mosaic embryos should be preferentially transferred over others. Transfer of embryos with mosaic trisomies 2, 7, 13, 14, 15, 16, 18, and 21 may pose the most risk of having a child affected with a trisomy syndrome; however, the transfer of embryos with mosaic monosomies or other mosaic trisomies are not devoid of risk. Patients must be counseled about the risk of undetected monosomies or trisomies within a biopsy specimen as well as the risk of intrauterine fetal demise or uniparental disomy with the transfer of mosaic embryos. Until more data are available, patients should be encouraged to undergo another cycle to obtain euploid embryos, when possible, rather than transferring a mosaic embryo.

Factors affecting recall of different types of personal genetic information about Alzheimer's disease risk: the REVEAL study.

METHODS: Data were obtained through a multisite clinical trial in which different types of genetic risk-related information were disclosed to individuals (n = 246) seeking a risk assessment for Alzheimer's disease. RESULTS: Six weeks after disclosure, 83% of participants correctly recalled the number of risk-increasing APOE alleles they possessed, and 74% correctly recalled their APOE genotype. While 84% of participants recalled their lifetime risk estimate to within 5 percentage points, only 51% correctly recalled their lifetime risk estimate exactly. Correct recall of the number of APOE risk-increasing alleles was independently associated with higher education (p < 0.001), greater numeracy (p < 0.05) and stronger family history of Alzheimer's disease (p < 0.05). Before adjustments for confounding, correct recall of APOE genotype was also associated with higher education, greater numeracy and stronger family history of Alzheimer's disease, as well as with higher comfort with numbers and European American ethnicity (all p < 0.05). Correct recall of the lifetime risk estimate was independently associated only with younger age (p < 0.05). CONCLUSIONS: Recall of genotype-specific information is high, but recall of exact risk estimates is lower. Incorrect recall of numeric risk may lead to distortions in understanding risk. Further research is needed to determine how best to communicate different types of genetic risk information to patients, particularly to those with lower educational levels and lower numeracy. Health-care professionals should be aware that each type of genetic risk information may be differentially interpreted and retained by patients and that some patient subgroups may have more problems with recall than others.