Perspectives of couples with high risk of transmitting genetic disorders

Preimplantation Genetic Testing for Adult-Onset Neurodegenerative Disease: Considerations for Access, Utilization, and Counseling

Preimplantation genetic testing for monogenic conditions (PGT-M), formerly called preimplantation genetic diagnosis, is a specialized assisted reproduction technique that aims to reduce the risk of a pregnancy inheriting a monogenic condition. Despite calls to increase awareness and prepare neurologists for discussing PGT-M with patients and their families, no guidelines currently exist. When introducing PGT-M to those who may be interested in using it, there are major factors for discussion, including (1) genetic considerations (e.g., requirement for a confirmed genetic diagnosis; timing of genetic test results); (2) practical considerations (e.g., access to PGT-M and genetic services); (3) technical considerations (e.g., factors that can affect the success rate of PGT-M); and (4) psychosocial and ethical considerations (e.g., predictive testing for asymptomatic family members; family dynamics and values). Here, our team of neurologists and specialized genetic counselors discusses the current state of genetic characterization in adult-onset neurodegenerative conditions and highlights the major factors that should be considered when discussing PGT-M with families.

Cost-effectiveness of IVF with PGT-M/A to prevent transmission of spinal muscular atrophy in offspring of carrier couples

PURPOSE

To evaluate the cost-effectiveness of in-vitro fertilization with preimplantation genetic testing for aneuploidy and monogenic disorders (IVF with PGT-M/A) to prevent transmission of spinal muscular atrophy to offspring of carrier couples.

METHODS

A decision-analytic model was created to compare the cost-effectiveness of IVF with PGT-M/A to unassisted conception with prenatal diagnostic testing and termination (if applicable). IVF with PGT-M/A costs were determined using a separate Markov state-transition model. IVF outcomes data was derived from 76 carriers of monogenic disorders who underwent IVF with PGT-M/A at a single academic REI center. Other probabilities, costs, and utilities were derived from the literature. Costs were modeled from healthcare perspective. Utilities were modeled from the parental perspective as quality-adjusted life-years (QALYs).

RESULTS

The incremental cost-effectiveness ratio for IVF with PGT-M/A compared to unassisted conception is $22,050 per quality-adjusted life-year. The average cost of IVF with PGT-M/A is $41,002 (SD: $8,355). At willingness-to-pay thresholds of $50,000 and $100,000, IVF with PGT-M/A is cost-effective 93.3% and 99.5% of the time, respectively.

CONCLUSIONS

Compared to unassisted conception, IVF with PGT-M/A is cost-effective for preventing the transmission of spinal muscular atrophy to the offspring of carrier couples. These findings support insurance coverage of IVF with PGT-M/A for carriers of spinal muscular atrophy.

Preimplantation genetic testing in two Danish couples affected by Peutz-Jeghers syndrome

BACKGROUND

Guidelines from the European Hereditary Tumor Group as well as The Danish National Guidelines for Peutz-Jeghers Syndrome (PJS) state that both prenatal diagnosis and preimplantation genetic testing for monogenic disorders (PGT-M) should be offered to patients with PJS. However, only a few cases resulting in viable pregnancies have been published.

OBJECTIVE

We present two cases of PJS patients going through PGT-M for PJS. We highlight the awareness of this possibility and discuss the technical and ethical challenges of performing PGT-M for PJS.

METHODS AND RESULTS

Case 1: A 36-year-old male with PJS and his partner were referred for genetic counseling. The patient carried a pathogenic de novo variant in STK11. After a terminated pregnancy of a fetus carrying the same pathogenic variant, microsatellite polymorphic marker analysis was established, and the patient was offered PGT-M. The female partner of the patient gave birth to a healthy boy after five years of fertility treatment. Case 2: A 35-year-old female with PJS and her partner were referred for genetic counseling. She carried an inherited pathogenic STK11 variant. The couple was offered PGT-M. Genetic testing of the embryos was performed using microsatellite polymorphic markers. After two rounds of oocyte extraction a blastocyst predicted not to be affected by PJS was identified. The blastocyst was transferred; however, this did not result in a viable pregnancy.

CONCLUSIONS

PGT-M can be offered to patients with PJS. The process may be long and filled with ethical dilemmas requiring patients to be motivated and persistent.

Use of Preimplantation Genetic Testing for Monogenic Disorders and Subsequent Prenatal Care and Diagnostic Testing

OBJECTIVE

The goal of preimplantation genetic testing for monogenic or single gene defects (PGT-M) is to identify inherited pathogenic variants in the embryo prior to embryo transfer, increasing the likelihood of an unaffected child. Prenatal diagnostic testing is recommended to confirm the results of PGT-M. The purpose of this study was to characterize the population undergoing PGT-M over time.

METHODS

This retrospective study examined patients who had a positive pregnancy test after PGT-M from 2012-2019. A query of the internal assisted reproductive technology database and chart review were used.

RESULTS

One hundred and forty-two patients completed IVF cycles for PGT-M during this time-period and progressed past 10-weeks gestation. There were more PGT-M cycles over time with 46 cycles between 2012 and 2015 and 96 cycles between 2016 and 2019. Patients varied on the decision to pursue prenatal diagnostic testing after PGT-M. For those with known follow-up (130/142) 16 patients underwent diagnostic testing (12%) and 114 did not.

CONCLUSION

As PGT-M is increasingly utilized prior to pregnancy, it is important for genetic counselors and OB/GYNs to understand the characteristics and outcomes of the population of patients undergoing PGT-M, including how to counsel about the residual risk of an affected pregnancy after PGT-M. This article is protected by copyright. All rights reserved.

Specialist physicians' referral behavior regarding preimplantation genetic testing for single-gene disorders: Is there room to grow?

Objective

To assess whether primary care specialists’ demographics, specialty, and knowledge of preimplantation genetic testing for monogenic disorders (PGT-M) influence their practice patterns.

Design

Cross-sectional survey study.

Setting

Academic medical center.

Patient(s)

Not applicable.

Intervention(s)

None.

Main Outcome Measure(s)

Objective PGT-M knowledge, subjective comfort with PGT-related topics, PGT care practices (discussions/referrals), and PGT-M implementation barriers.

Result(s)

Our survey had 145 respondents: 65 obstetrician/gynecologists, 36 internists, and 44 pediatricians. Overall, 88% believed that patients at a risk of passing on genetic disorders should be provided PGT-M information. However, few discussed PGT-M with their patients (24%) or referred them for testing (23%). Over half (63%) believed that the lack of physician knowledge was a barrier to PGT use. In terms of subjective comfort with PGT, only 1 in 5 physicians felt familiar enough with the topic to answer patient questions. There were higher odds of discussing (odds ratio, 3.21; 95% confidence interval, 1.75–5.87) or referring for PGT (odds ratio, 2.52; 95% confidence interval, 1.41–4.51) for each additional 0.5 correct answers to PGT knowledge-related questions. The odds of referring patients for PGT-M were the highest among obstetrician/gynecologists compared with those among the internists and pediatricians.

Conclusion(s)

Physician specialty and PGT knowledge were associated with PGT-M care delivery practices. Although most specialists believed in equipping at-risk patients with PGT-M information, <1 in 4 discussed or referred patients for PGT. The low levels of PGT-related care among providers may be owed to inadequate knowledge of and comfort with the topic. An opportunity to promote greater understanding of PGT-M among primary care specialists exists and can in turn improve the use of referrals to PGT-M services.

Review: Preimplantation genetic diagnosis (PGD) as a reproductive option in patients with neurodegenerative disorders

Preimplantation genetic diagnosis (PGD) was introduced in the late 1980s and represents an option for couples at risk of transmitting an inherited, debilitating or neurological disorder to their children. From a cleavage or blastocyst stage embryo, cell(s) are collected and then genetically analyzed for disease; enabling an unaffected embryo to be transferred into the uterus cavity. Nowadays, PGD has been carried out for several hundreds of heritable conditions including myotonic dystrophy, and for susceptibility genes involved in cancers of the nervous system. Currently, advanced molecular technologies with better resolution, such as array comparative genomic hybridisation, quantitative polymerase chain reaction, and next generation sequencing, are on the verge of becoming the gold standard in embryo preimplantation screening. Given this, it may be time for neurological societies to consider the published evidence to develop new guidelines for the integration of PGD into modern preventative neurology. Therefore, the main aim of this review is to illustrate the option of PGD to enable conception of an unaffected baby, and to assist clinicians and neurologists in the counseling of the patient at risk of transmitting an inherited disease, to explore the genetic journey throughout in vitro fertilization IVF with PGD.

In vitro fertilisation with preimplantation genetic testing: the need for expanded insurance coverage

Technological advances in genetic testing have enabled prospective parents to learn about their risk of passing a genetic condition to their future children. One option for those who want to ensure that their biological children do not inherit a genetic condition is to create embryos through in vitro fertilisation (IVF) and use a technique called preimplantation genetic testing (PGT) to screen embryos for genetic abnormalities before implantation. Unfortunately, due to its high cost, IVF-with-PGT is out of reach for the vast majority of Americans. This article addresses an issue that has been underexplored in the medical ethics literature: the lack of insurance coverage for IVF-with-PGT.Within the US system, a key concept in insurance is that of medically necessary care, which broadly consists of diagnostic services and treatment services. In this article, I argue that IVF-with-PGT could be classified as either a diagnostic service or as a treatment service. To make this case, I show that IVF-with-PGT is similar to other types of services that are often covered by US insurance providers. In light of these similarities, I argue that the current system is inconsistent with respect to what is-and is not-covered by insurance. To promote consistency and fairness in coverage, like cases should be treated alike-starting with greater coverage for IVF-with-PGT.

Literacy assessment of preimplantation genetic patient education materials exceed national reading levels

PURPOSE

In vitro fertilization with preimplantation genetic testing (IVF+PGT-M) reduces the risk of having a child affected by a heritable condition, yet only one-third of eligible patients are aware of this reproductive option. Access to education materials written at appropriate literacy levels could raise patients' awareness, but there is a mismatch between patient reading ability and the literacy demand of most materials. This study aimed to systematically identify written education materials on IVF+PGT-M and evaluate their literacy levels. We hypothesized that materials would fail to meet standards set by the Joint Commission and Centers for Disease Control and Prevention (CDC).

METHODS

To identify patient education materials about IVF+PGT-M from academic databases and public-facing sources, an environmental scan was performed. Materials were analyzed using three validated scales: Simple Measure of Gobbledygook, Patient Education Materials Assessment Tool, and Clear Communication Index.

RESULTS

Seventeen patient education materials about IVF+PGT-M were identified from patient education databases, a consumer search engine, and professional organizations. The median reading level was 14.5 grade, median understandability was 74.2%, and median comprehensibility was 73.3%.

CONCLUSIONS

For most American adults, materials about IVF+PGT-M are not readable, understandable, or clear. The Joint Commission requires patient education materials be written at or below 5th grade reading level and the CDC recommends a 90% minimum score for comprehensibility. No evaluated material met these guidelines. Patient education materials that exceed average American literacy skills may perpetuate disparities in the utilization of IVF+PGT-M. Materials that communicate this complicated subject at an understandable level are needed.

Prenatal diagnosis in a hereditary Peutz-Jeghers syndrome family with high cancer risk

BACKGROUND

Peutz-Jeghers Syndrome (PJS) is a hereditary cancer predisposing syndrome caused by autosomal dominant mutations in the serine/threonine kinase 11 (STK11) gene and is associated with decreased life expectancy. Many families experience a poorer quality of life due to the psychological burden associated with the carrier status of their child. Therefore early genetic testing and confirmation of the diagnosis is important for patients' psychological status, as well as for clinical management, genetic counseling and possible prenatal family planning.

METHODS

In this study, peripheral blood genomic DNA samples from a Chinese PJS family with a high cancer risk were examined for STK11 mutations using Sanger sequencing and MLPA analysis. Furthermore, prenatal PJS testing from transabdominal chorionic villi sample was performed in one female member of the family. This family was followed up for three years.

RESULTS

In this family, the STK11 exon 1 deletion (c.-1114-?_290 +?del) was predicted to affect the kinase domain of the protein and co-segregated with the disease phenotype. The same mutation was detected in the fetus and genetic sequencing and MLPA of the infant's DNA and the pigmentation on his lips confirmed the result of prenatal testing. To the best of our knowledge, this is the first report on PJS prenatal diagnosis of a PJS family in China.

CONCLUSIONS

An accurate and convenient PJS prenatal testing provides an opportunity for affected families to focus on polyp-related symptoms and cancer prevention and may be helpful for couples in family planning decision-making.

Organisation of care for pregnancy in patients with congenital heart disease

Improvements in surgery have resulted in more women with repaired congenital heart disease (CHD) surviving to adulthood. Women with CHD, who wish to embark on pregnancy require prepregnancy counselling. This consultation should cover several issues such as the long-term prognosis of the mother, fertility and miscarriage rates, recurrence risk of CHD in the baby, drug therapy during pregnancy, estimated maternal risk and outcome, expected fetal outcomes and plans for pregnancy. Prenatal genetic testing is available for those patients with an identified genetic defect using pregestational diagnosis or prenatal diagnosis chorionic villus sampling or amniocentesis. Centralisation of care is needed for high-risk patients. Finally, currently there are no recommendations addressing the issue of the delivery. It is crucial that a dedicated plan for delivery should be available for all cardiac patients. The maternal mortality in low-income to middle-income countries is 14 times higher than in high-income countries and needs additional aspects and dedicated care.

Reproductive outcome following pre-implantation genetic diagnosis (PGD) in the UK

In 2013, the National Health Service Commissioning board centralized the funding in England for up to three cycles of pre-implantation genetic diagnosis (PGD) for couples who have, or are carriers of, a specific genetic disorder. This study presents the historical data of PGD cycles and their clinical outcomes in UK as extrapolated from the national data registry. Retrospective analysis of outcome of cycles undergoing pre-implantation genetic diagnosis in the UK over the past 20 years was performed from the Human Fertilisation and Embryology Authority database (n = 2974). Binary logistic regression was used to determine trends over time and adjusted for maternal age. Briefly, the number of PGD cycles has risen 127-fold from 1991 to 2012 with 3.6-fold increase (360% rise) from 2004 to 2012. A total of one in four embryos following pre-implantation genetic diagnosis did not reach embryo transfer and 92% of these were due to a failure to survive. The live birth rate has risen over 20 years and there has been a steady decline in reported incidence of congenital abnormalities (p < 0.07). PGD has thus emerged as a safe and effective alternative to prenatal diagnosis but with ever evolving technological advances, a robust system of data collection that incorporates techniques used and reporting of mutation-specific clinical outcomes is suggested.

Rapid Identification of Pathogenic Variants in Two Cases of Charcot-Marie-Tooth Disease by Gene-Panel Sequencing

Charcot-Marie-Tooth disease (CMT) is a common inherited peripheral neuropathy affecting up to 1 in 1214 of the general population with more than 60 nuclear genes implicated in its pathogenesis. Traditional molecular diagnostic pathways based on relative prevalence and clinical phenotyping are limited by long turnaround time, population-specific prevalence of causative variants and inability to assess multiple co-existing variants. In this study, a CMT gene panel comprising 27 genes was used to uncover the pathogenic mutations in two index patients. The first patient is a 15-year-old boy, born of consanguineous parents, who has had frequent trips and falls since infancy, and was later found to have inverted champagne bottle appearance of bilateral legs and foot drop. His elder sister is similarly affected. The second patient is a 37-year-old woman referred for pre-pregnancy genetic diagnosis. During early adulthood, she developed progressive lower limb weakness, difficulties in tip-toe walking and thinning of calf muscles. Both patients are clinically compatible with CMT, have undergone multiple genetic testings and have not previously received a definitive genetic diagnosis. Patients 1 and 2 were found to have pathogenic homozygous HSPB1:NM_001540:c.250G>A (p.G84R) variant and heterozygous GDAP1:NM_018972:c.358C>T (p.R120W) variant, respectively. Advantages and limitations of the current approach are discussed.

Establishment of human-embryonic-stem-cell line from mosaic trisomy 9 embryo

OBJECTIVE

Human-embryonic-stem-cell (hESC) lines derived from chromosomally or genetically abnormal embryos obtained following preimplantation genetic diagnosis are valuable in investigating genetic disorders.

MATERIALS AND METHODS

In this study, a new hESC line, Center of Clinical Reproductive Medicine 8 (CCRM8) was established by isolation, culture, and passaging of the inner cell mass of mosaic trisomy 9 embryos.

RESULTS

A karyotype analysis showed that the hESC line possessed a euploid (46 chromosomes). The undifferentiated hESCs exhibited long-term proliferation capacity and expressed typical markers of OCT4, TRA-1-60, and TRA-1-81. In vitro embryoid-body (EB) formation, differentiation, and in vivo teratoma production confirmed the pluripotency of the hESC line. The data represented here are the first detailed report on the characterization and differentiation of one Chinese hESC line generated from mosaic trisomy 9 embryos.

CONCLUSION

Our study showed that chromosomally aberrant embryos could generate a normal hESC line, which would be useful in investigating gene function and embryo development.

Recurrent miscarriage in translocation carriers: no differences in clinical characteristics between couples who accept and couples who decline PGD

STUDY QUESTION

Do clinical characteristics of recurrent miscarriage couples with a chromosomal abnormality and who opt for PGD differ from couples that decline PGD after extensive genetic counselling?

SUMMARY ANSWER

No differences in clinical characteristics are identified between recurrent miscarriage couples carrying a structural chromosomal abnormality who opt for PGD compared with those that decline PGD after extensive genetic counselling.

WHAT IS KNOWN ALREADY

Couples who have experienced two or more miscarriages (recurrent miscarriage) are at increased recurrence risk if one of the partners carries a structural chromosomal abnormality. PGD can be offered to avoid (another) miscarriage or pregnancy termination when (invasive) prenatal diagnosis shows an abnormal result. To date, no reports are available that describe reproductive decision-making after genetic counselling on PGD in these specific couples.

STUDY DESIGN, SIZE, DURATION

Retrospective cohort study of 294 couples carrying a structural chromosomal abnormality seeking genetic counselling on PGD between 1996 and 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were recurrent miscarriage couples carrying a structural chromosomal abnormality. They had been referred for genetic counselling to the only national licensed PGD centre. Clinical characteristics analysed included couple associated characteristics, characteristics concerning reproductive history and external characteristics such as type of physician that referred the couple for genetic counselling and the clinical geneticist performing the counselling on PGD.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 294 couples referred for counselling on PGD, 26 were not accepted because they did not meet the criteria for IVF-PGD. The remaining cohort of 268 couples consisted of two-thirds female and one-third male carriers. Main PGD indications were reciprocal translocations (83.9%) and Robertsonian translocations (16.7%). Following genetic counselling, 76.9% of included couples chose PGD as their reproductive option, the others declined PGD. Reproductive choice is not influenced by sex of the translocation carrier (P = 0.499), type of chromosomal abnormality (P = 0.346), number of previous miscarriages (P = 0.882), history of termination of pregnancy (TOP) because of an unbalanced fetal karyotype (P = 0.800), referring physician (P = 0.208) or geneticist who performed the counselling (P = 0.410).

LIMITATIONS, REASONS FOR CAUTION

This study only included recurrent miscarriage couples carrying a structural chromosomal abnormality, who were actually referred to a PGD clinic for genetic counselling. We lack information on couples who were not referred for PGD. Some of these patients may not have been informed on PGD at all, while others were not referred for counselling because they did not opt for PGD to start with.

WIDER IMPLICATIONS OF THE FINDINGS

This study shows that reproductive choices in couples with recurrent miscarriage on the basis of a structural chromosomal abnormality are not influenced by characteristics of the couple itself, nor by their obstetric history or external characteristics. These findings suggest that a couples' intrinsic attitude towards PGD treatment is a major factor influencing their reproductive choice. Future research will focus on these personal motives that seem to push reproductive decision-making following genetic counselling in a given direction.

Preimplantation genetic diagnosis for inherited neurological disorders

Preimplantation genetic diagnosis (PGD) is an option for couples at risk of having offspring with an inherited debilitating or fatal neurological disorder who wish to conceive a healthy child. PGD has been carried out for conditions with various modes of inheritance, including spinal muscular atrophy, Huntington disease, fragile X syndrome, and chromosomal or mitochondrial disorders, and for susceptibility genes for cancers with nervous system involvement. Most couples at risk of transmitting a genetic mutation would opt for PGD over prenatal testing and possible termination of a pregnancy. The aim of this Perspectives article is to assist neurologists in counselling and treating patients who wish to explore the option of PGD to enable conception of an unaffected child. PGD can be accomplished for most disorders in which the genetic basis is known, and we argue that it is time for clinicians and neurological societies to consider the evidence and to formulate guidelines for the responsible integration of PGD into modern preventative neurology.

Peutz-Jeghers syndrome and family planning: the attitude towards prenatal diagnosis and pre-implantation genetic diagnosis

Peutz-Jeghers syndrome (PJS) is a hereditary disorder caused by LKB1 gene mutations, and is associated with considerable morbidity and decreased life expectancy. This study was conducted to assess the attitude of PJS patients towards family planning, prenatal diagnosis (PND) and pregnancy termination, and pre-implantation genetic diagnosis (PGD). In a cross-sectional study, 61 adult PJS patients were asked to complete a questionnaire concerning genetic testing, family planning, PND and PGD. The questionnaire was completed by 52 patients (85% response rate, 44% males) with a median age of 44 (range 18-74) years. A total of 37 (71%) respondents had undergone genetic testing. In all, 24 respondents (46%, 75% males) had children. A total of 15 (29%) respondents reported that their diagnosis of PJS had influenced their decisions regarding family planning, including 10 patients (19%, 9/10 females) who did not want to have children because of their disease. Termination of pregnancy after PND in case of a foetus with PJS was considered 'acceptable' for 15% of the respondents, whereas 52% considered PGD acceptable. In conclusion, the diagnosis of PJS influences the decisions regarding family planning in one third of PJS patients, especially in women. Most patients have a negative attitude towards pregnancy termination after PND, while PGD in case of PJS is judged more acceptable. These results emphasise the importance of discussing aspects regarding family planning with PJS patients, including PND and PGD.

PGD for all cystic fibrosis carrier couples: novel strategy for preventive medicine and cost analysis

Over 1000 children affected with cystic fibrosis (CF) are born annually in the USA. Since IVF with preimplantation genetic diagnosis (PGD) is an alternative to raising a sick child or to aborting an affected fetus, a cost-benefit analysis was performed for a national IVF-PGD program for preventing CF. The amount spent to deliver healthy children for all CF carrier-couples by IVF-PGD was compared with the average annual and lifetime direct medical costs per CF patient avoided. Treating annually about 4000 CF carrier-couples with IVF-PGD would result in 3715 deliveries of non-affected children at a cost of $57,467 per baby. Because the average annual direct medical cost per CF patient was $63,127 and life expectancy is 37 years, savings would be $2.3 million per patient and $2.2 billion for all new CF patients annually in lifetime treatment costs. Cumulated net saving of an IVF-PGD program for all carrier-couples for 37 years would be $33.3 billion. A total of 618,714 cumulative years of patients suffering because of CF and thousands of abortions could be prevented. A national IVF-PGD program is a highly cost-effective novel modality of preventive medicine and would avoid most births of individuals affected with debilitating genetic disease.