Preimplantation genetics and other reproductive options in Huntington disease

Diagnostic outcome of pro bono neurogenetic diagnostic service in Sri Lanka: A wealth creation

The inherited disease community in Sri Lanka has been widely neglected. This article aimed to present accumulated knowledge in establishing a pro bono cost-effective national, island-wide, free-of-charge molecular diagnostic service, suggesting a model for other developing countries. The project provided 637 molecular diagnostic tests and reports free of charge to a nation with limited resources. We pioneered the implementation of mobile clinics and home visits, where the research team acted as barefoot doctors with the concept of the doctor and the researcher at the patient's doorstep. Establishing pro bono, cost-effective molecular diagnostics is feasible in developing countries with limited resources and state funding through the effort of dedicated postgraduate students. This service could provide an accurate molecular diagnosis of Duchenne muscular dystrophy, Huntington's disease, Spinocerebellar ataxia, and Spinal muscular atrophy, a diagnostic yield of 54% (343/637), of which 43% (147/343) of the patients identified as amenable for available gene therapies. Initiated human resource development by double doctoral degree opportunities with international collaborations. Established a neurobiobank and a national registry in Sri Lanka, a rich and unique repository, wealth creation for translational collaborative research and sharing of information in neurological diseases, as well as a lodestar for aspiring initiatives from other developing countries.

The far-reaching impact of abortion bans: reproductive care and beyond

On 24 June 2022, the US Supreme Court overturned Roe v. Wade, a 49-year-old precedent that provided federal constitutional protection for abortions up to the point of foetal viability, returning jurisdiction to the individual states. Restrictions that came into effect automatically in several states, and are anticipated in others, will severely limit access to abortions in approximately half of the US. Even though every state allows for exceptions to the abortion bans, in some instances these exceptions can be used to preserve the health of a pregnant patient, while in other instances, only to preserve their life. The vague and confusing nature of the abortion ban exceptions threatens to compromise the standard of care for patients with pregnancy complications that are distinct from abortions, such as nonviable pregnancies, miscarriages, and ectopic pregnancies. Additionally, we envision challenges for the treatment of women with certain autoimmune conditions, pregnant cancer patients, and patients contemplating preimplantation genetic diagnosis as part of assisted reproductive technologies. The abortion ban exceptions will impact and interfere with the medical care of pregnant and non-pregnant patient populations alike and are poised to create a medical and public health crisis unlike any other one from the recent past.

In vitro fertilization with preimplantation genetic testing for monogenetic diseases versus unassisted conception with prenatal diagnosis for Huntington disease: a cost-effectiveness analysis

OBJECTIVE

To investigate if in vitro fertilization (IVF) with preimplantation genetic testing for monogenic disease is cost effective for heterozygous individuals with Huntington disease vs. unassisted conception with prenatal diagnosis.

DESIGN

Cost-effectiveness analysis in a theoretical cohort of 3,851 couples, where one individual is heterozygous for Huntington disease.

SETTING

N/A.

PATIENTS/ANIMALS

None.

INTERVENTION

In vitro fertilization preimplantation genetic testing for couples attempting conception.

MAIN OUTCOME MEASURES

Outcomes included cost and quality-adjusted life years (QALYs) for both parents in addition to secondary outcomes of procedure-related loss, spontaneous abortion, termination of pregnancy, and early/normal/late-onset Huntington disease. A willingness-to-pay threshold was set at $100,000/QALY.

RESULTS

In vitro fertilization preimplantation genetic testing is lower in cost and higher in effectiveness compared to unassisted conception with prenatal diagnosis among couples with one heterozygous Huntington disease individual, making it the dominant strategy. In vitro fertilization preimplantation genetic testing was associated with 77 more QALYs and a cost savings of $46,394,268. All measured outcomes were lower in the IVF preimplantation genetic testing strategy, including 39 fewer procedure-related losses, 39 fewer spontaneous abortions, and 462 fewer terminations of pregnancy. Most notably, in our theoretical cohort of couples, IVF preimplantation genetic testing resulted in 1,079 fewer Huntington disease-affected offspring. Our results were robust over a wide range of assumptions.

CONCLUSION

In vitro fertilization preimplantation genetic testing is a cost-effective conception strategy compared to unassisted conception with prenatal diagnosis when one individual is heterozygous for Huntington disease. Not only can morbidity and mortality incurred by Huntington disease be mitigated for the offspring with the use of IVF preimplantation genetic testing, but this study demonstrates the cost-effectiveness of using IVF preimplantation genetic testing for those with Huntington disease.

Comprehensive genetic diagnosis of tandem repeat expansion disorders with programmable targeted nanopore sequencing

More than 50 neurological and neuromuscular diseases are caused by short tandem repeat (STR) expansions, with 37 different genes implicated to date. We describe the use of programmable targeted long-read sequencing with Oxford Nanopore's ReadUntil function for parallel genotyping of all known neuropathogenic STRs in a single assay. Our approach enables accurate, haplotype-resolved assembly and DNA methylation profiling of STR sites, from a list of predetermined candidates. This correctly diagnoses all individuals in a small cohort (n = 37) including patients with various neurogenetic diseases (n = 25). Targeted long-read sequencing solves large and complex STR expansions that confound established molecular tests and short-read sequencing and identifies noncanonical STR motif conformations and internal sequence interruptions. We observe a diversity of STR alleles of known and unknown pathogenicity, suggesting that long-read sequencing will redefine the genetic landscape of repeat disorders. Last, we show how the inclusion of pharmacogenomic genes as secondary ReadUntil targets can further inform patient care.