Treatment Of Genetic Diseases Research Articles

Nanotechnology and CRISPR/Cas-Mediated Gene Therapy Strategies: Potential Role for Treating Genetic Disorders.

Gene therapy has made substantial progress in the treatment of the genetic diseases, focussing on the reduction of characteristics of recessive/dominant disorders, as well as various cancers. Extensive research has been conducted in the past few decades to investigate the application of nanotechnology and CRISPR/Cas technology in gene therapy. Nanotechnology due to attributes such has targeted drug delivery, controlled release, scalability and low toxicity has gained attention of the medical world. CRISPR/Cas9 system is considered as an impactful genome editing tool in the area of next-generation therapeutics and molecular diagnostics. CRISPR technology emphasises on gene editing, gene regulation modulation, and formulation of defined genetic changes. Its applications in treatment of the genetic disorders are extended beyond traditional therapies. These techniques are being explored as treatment of several genetic disorders including Duchenne muscular dystrophy, cystic fibrosis, Alzheimer's disease, Parkinson's disease, and Huntington disease. Despite considerable therapeutic potential of gene therapy, several obstacles must be addressed before it can be widely adopted in clinical practice, particularly in terms of ensuring safety and effectiveness. As research advances in this captivating field, these therapies will become the primary treatments and will have significant beneficial effects on the lives of patients with genetic disorders.

Identification of SLC35A1 as an essential host factor for the transduction of multi-serotype recombinant adeno-associated virus (AAV) vectors.

rAAV is an essential tool for gene delivery in the treatment of genetic disorders, yet the mechanisms of rAAV transduction remain partially understood. GPR108 is vital for the transduction of most rAAV vectors, but not for rAAV5. We aimed to identify host factors that impact AAV5 transduction akin to GPR108. Using a genome-wide CRISPR/Cas9 screen in 293-F cells, we identified SLC35A1, a Golgi apparatus-localized CMP-sialic acid transporter that transports CMP-sialic acid from cytoplasm into the Golgi apparatus for sialylation, is essential to rAAV transduction. Further studies across various AAV serotypes showed SLC35A1 significantly affects vector nuclear import post-internalization. These results underscore the crucial role of SLC35A1 in intracellular trafficking beyond the initial cell attachment of rAAV.

AAVolve: Concatenated long-read deep sequencing enables whole capsid tracking during shuffled AAV library selection

Gene therapies using recombinant adeno-associated virus (AAV) vectors have demonstrated considerable clinical success in the treatment of genetic disorders. Improved vectors with favourable tropism profiles, decreased immunogenicity and enhanced manufacturability are poised to further improve the state of gene therapies. Such vectors can be identified through directed evolution, a process of subjecting a diverse capsid library to a selection pressure to identify individual variants with a desired trait. Currently, libraries that involve changes distributed throughout the AAV capsid coding region, such as DNA family shuffled libraries, are largely characterised using low-throughput Sanger sequencing of individual clones. However, improvements in long-read sequencing technologies have increased their applicability to capsid libraries and evaluation of the selection process. Here we explore the application of Oxford Nanopore Technologies refined by a concatemeric consensus method for initial library characterization and monitoring selection of a shuffled AAV capsid library. Furthermore, we present AAVolve, a bioinformatic pipeline for processing long-read data from AAV directed evolution experiments. Our approach allows high throughput characterisation of AAV capsids in a streamlined manner, facilitating deeper insights into library composition through multiple rounds of selection, and generalization through training of machine learning models.

An AAV capsid reprogrammed to bind human transferrin receptor mediates brain-wide gene delivery.

Developing vehicles that efficiently deliver genes throughout the human central nervous system (CNS) will broaden the range of treatable genetic diseases. We engineered an adeno-associated virus (AAV) capsid, BI-hTFR1, that binds human transferrin receptor (TfR1), a protein expressed on the blood-brain barrier. BI-hTFR1 was actively transported across human brain endothelial cells and, relative to AAV9, provided 40 to 50 times greater reporter expression in the CNS of human TFRC knockin mice. The enhanced tropism was CNS-specific and absent in wild-type mice. When used to deliver GBA1, mutations of which cause Gaucher disease and are linked to Parkinson's disease, BI-hTFR1 substantially increased brain and cerebrospinal fluid glucocerebrosidase activity compared with AAV9. These findings establish BI-hTFR1 as a potential vector for human CNS gene therapy.

When rare meets common: Treatable genetic diseases are enriched in the general psychiatric population.

Mental illnesses are one of the biggest contributors to the global disease burden. Despite the increased recognition, diagnosis and ongoing research of mental health disorders, the etiology and underlying molecular mechanisms of these disorders are yet to be fully elucidated. Moreover, despite many treatment options available, a large subset of the psychiatric patient population is nonresponsive to standard medications and therapies. There has not been a comprehensive study to date examining the burden and impact of treatable genetic disorders (TGDs) that can present with neuropsychiatric features in psychiatric patient populations. In this study, we test the hypothesis that TGDs that present with psychiatric symptoms are more prevalent within psychiatric patient populations compared to the general population by performing targeted next-generation sequencing of 129 genes associated with 108 TGDs in a cohort of 2301 psychiatric patients. In total, 48 putative affected and 180 putative carriers for TGDs were identified, with known or likely pathogenic variants in 79 genes. Despite screening for only 108 genetic disorders, this study showed a two-fold (2.09%) enrichment for genetic disorders within the psychiatric population relative to the estimated 1% cumulative prevalence of all single gene disorders globally. This strongly suggests that the prevalence of these, and most likely all, genetic diseases is greatly underestimated in psychiatric populations. Increasing awareness and ensuring accurate diagnosis of TGDs will open new avenues to targeted treatment for a subset of psychiatric patients.

The History, Use, and Challenges of Therapeutic Somatic Cell and Germline Gene Editing

ABSTRACT Gene editing is a technology that has been rapidly developing and that has many applications as well as ethical and practical implications. This article is a review that outlines the history of current technology, as well as the advantages and challenges in use for somatic cell and germline gene editing. Clustered regularly interspaced short palindromic repeat (CRISPR) was first introduced in 2002 and initially saw limited use among researchers. However, in 2012, it was discovered that a nuclease associated with CRISPR (Cas9) could be used with guide RNA to cleave double-stranded DNA in specific places, raising the potential for targeted gene editing. Immediately, the scientific community saw endless possibilities of this technology for clinical therapies and treatment of genetic disorders. Currently, more than 110 gene editing–based therapies are in clinical trials, with 2 different treatments already in phase 3 clinical trials. To date, all gene editing therapies that have progressed to clinical trials are somatic cell editing therapies. Germline gene editing, in which changes to genes can be passed to the next generation, is attractive for inherited diseases but has many ethical considerations and challenges that must be addressed before this technology is further developed. One concern is off-target editing events that could involve DNA sequences with high similarity to the target sequence. In addition to this, DNA breaks from Cas9 can result in chromosomal instability and possible abnormalities such as large deletions, translocations, and rearrangements. This could be problematic particularly in germline editing, where the effects are passed down to the next generation. Gene editing does, however, have great potential. Somatic cell gene editing has been successfully used to prevent and treat disease. One advantage of somatic cells is that they can be removed, edited, and returned to the patient to proliferate normally. For the therapies currently in stage 3 clinical trials, there have been few instances of failure to modify the alleles and no evidence of off-target editing using this method. Somatic cell gene editing has successfully been used in animal models and in limited human trials to treat diseases with easily accessible in vivo sites, such as the eye. Germline gene editing has advantages over somatic cell gene editing, as therapies can be developed to permanently correct heritable genetic diseases. It could also be adapted easily during an in vitro fertilization process for parents who are carriers of 1 or more diseases to eliminate the risk of their offspring manifesting the disease. However, germline editing creates changes to the DNA that is then passed to offspring, raising ethical and safety concerns. Many trials in animal models as well as early human clinical trials show promise for these treatments, but challenges remain including costs and logistical considerations such as time, space, and expertise. Another challenge is that because these therapies are targeted, each variation of each disease must be treated differently, with a therapy developed specifically for each disease and potentially even variations of the same disease. This again represents significant challenges related to cost, time, and expertise. Ethical challenges for germline gene editing include the use of human embryos, high rates of off-target editing, and possible severe chromosomal deletions depending on the target. Large chromosomal rearrangements, as required with attempting to eradicate certain diseases, have been recently shown to be more difficult and dangerous than smaller rearrangements. This presents a unique challenge that must be overcome before implementing this technique in any therapies. There are many possibilities and exciting opportunities with gene editing therapies, some of which are closer to fruition than others. We are potentially close to implementing some therapies, such as those for sickle cell disease, while farther from broad use for other therapies. The pace at which this technology has developed is astounding, which brings hope that this research will continue to progress quickly, and we may be closer than we think to effectively treating genetic disease with gene editing technology.

Applications of Gene Editing and Gene Therapy in the Treatment of Genetic Disorders

Applications of Gene Editing and Gene Therapy in the Treatment of Genetic Disorders

A New RNA-Dependent Cas12g Nuclease

The development of RNA-targeting CRISPR-Cas systems represents a major step forward in the field of gene editing and regulation. RNA editing presents a viable alternative to genome editing in certain scenarios as it offers a reversible and manageable approach, reducing the likelihood of runaway mutant variants. One of the most promising applications is in the treatment of genetic disorders caused by mutations in RNA molecules. In this study, we investigate a previously undescribed Cas12g nuclease which was found in metagenomes from promising thermophilic microbial communities during the expedition to the Republic of North Ossetia—Alania in 2020. The method outlined in this study can be applied to other Cas orthologs and variants, leading to a better understanding of the CRISPR-Cas system and its enzymatic activities. The cis-cleavage activity of the new type V-G Cas effector was indicated by in vitro RNA cleavage experiments. While CRISPR-Cas systems are known for their high specificity, there is still a risk of unintended cleavage of nontargeted RNA molecules. Ultimately, the search for new genome editing tools and the study of their properties will remove barriers to research in this area. With continued research and development, we may be able to unlock their full potential.

NBSTRN Tools to Advance Newborn Screening Research and Support Newborn Screening Stakeholders.

Rapid advances in the screening, diagnosis, and treatment of genetic disorders have increased the number of conditions that can be detected through universal newborn screening (NBS). However, the addition of conditions to the Recommended Uniform Screening Panel (RUSP) and the implementation of nationwide screening has been a slow process taking several years to accomplish for individual conditions. Here, we describe web-based tools and resources developed and implemented by the newborn screening translational research network (NBSTRN) to advance newborn screening research and support NBS stakeholders worldwide. The NBSTRN's tools include the Longitudinal Pediatric Data Resource (LPDR), the NBS Condition Resource (NBS-CR), the NBS Virtual Repository (NBS-VR), and the Ethical, Legal, and Social Issues (ELSI) Advantage. Research programs, including the Inborn Errors of Metabolism Information System (IBEM-IS), BabySeq, EarlyCheck, and Family Narratives Use Cases, have utilized NBSTRN's tools and, in turn, contributed research data to further expand and refine these resources. Additionally, we discuss ongoing tool development to facilitate the expansion of genetic disease screening in increasingly diverse populations. In conclusion, NBSTRN's tools and resources provide a trusted platform to enable NBS stakeholders to advance NBS research and improve clinical care for patients and their families.

Feasibility of Targeted Next-Generation DNA Sequencing for Expanding Population Newborn Screening.

Newborn screening (NBS) is an effective public health intervention that reduces death and disability from treatable genetic diseases, but many conditions are not screened due to a lack of a suitable assay. Whole genome and whole exome sequencing can potentially expand NBS but there remain many technical challenges preventing their use in population NBS. We investigated if targeted gene sequencing (TGS) is a feasible methodology for expanding NBS. We constructed a TGS panel of 164 genes which screens for a broad range of inherited conditions. We designed a high-volume, low-turnaround laboratory and bioinformatics workflow that avoids the technical and data interpretation challenges associated with whole genome and whole exome sequencing. A methods-based analytical validation of the assay was completed and test performance in 2552 newborns examined. We calculated annual birth estimates for each condition to assess cost-effectiveness. Assay analytical sensitivity was >99% and specificity was 100%. Of the newborns screened, 1.3% tested positive for a condition. On average, each individual had 225 variants to interpret and 1.8% were variants of uncertain significance (VUS). The turnaround time was 7 to 10 days. Maximum batch size was 1536 samples. We demonstrate that a TGS assay could be incorporated into an NBS program soon to increase the number of conditions screened. Additionally, we conclude that NBS using TGS may be cost-effective.

A Review of the Use of Genetic Engineering Practices and the Impact of Gene Editing in Healthcare and Biotechnology

Genetic engineering is an integral approach to the development of new diagnostic techniques, drugs for human and animal diseases, foods for human health, development of tissues, and cells for xenotransplantation. The components of vaccine for disease control and nutraceuticals for human health provide proteins; peptides and other components may be an integral part of human life in the coming days. Genetically engineered animals also offer significant human health and environmental benefits; livestock becomes more efficient for converting feed to animal protein and reducing waste production, by imparting resistance to disease and good health. The techniques permit individuals or groups of genes to be isolated from large masses of DNA and produced in virtually unlimited quantities. Genetic engineering in animal production has a growing number of practical benefits, such as in the production of transgenic animal’s resistant to disease, increasing the productivity of animals, in the treatment of genetic disorders, and the production of vaccines.

Genomic Newborn Screening: Baby Steps into the Future.

Newborn screening (NBS) is a premier public health program which has grown in scope over several decades (1). Its primary goals are to identify early-onset, cost-effective, and treatable diseases at birth (1). Initially introduced in the 1960s to detect phenylketonuria by Dr. Robert Guthrie in Buffalo, NY, NBS is now mandated in multiple countries and has continued to be explored as a global human rights initiative (1). Tandem mass spectrometry and biochemical assays are the most utilized methods in NBS programs (1). However, with recent advancements in DNA sequencing technology, genome sequencing (or whole-genome sequencing), capable of detecting nearly all DNA variation in a genome, is being explored as a novel means to screen for rare genetic diseases at birth. At the 2022 inaugural International Conference on Newborn Sequencing (ICoNS) in Boston, several investigator teams from around the world highlighted their pilot screening programs’ goals in sequencing hundreds to thousands of newborns (2). One notable study presented at ICoNS recently announced by Genomics England is currently underway to sequence 100 000 newborns at birth to potentially identify 200 rare genetic diseases, which could help facilitate faster access to care (3). The study is expected to take 2 years, and will have further goals of understanding cost-effectiveness and overall parental acceptance. In addition, although the data will be used to detect genetic conditions, the children’s sequencing profiles will be stored on file for future identification of untreatable, adult-onset conditions, or other genetically determined traits (3). The storage of this data over time may help update the treatable genetic disease lists sooner and may assist in the development of therapeutics for rare conditions by identifying potential participants for clinical trials at a younger age (2).

PASTE, Don't Cut: Genome Editing Tool Looks Beyond CRISPR and Prime

PASTE, Don't Cut: Genome Editing Tool Looks Beyond CRISPR and Prime

Intracellular Delivery of mRNA for Cell-Selective CRISPR/Cas9 Genome Editing using Lipid Nanoparticles.

Messenger RNA (mRNA) is being used as part of an emerging class of biotherapeutics with great promise for preventing and treating a wide range of diseases, as well as encoding programmable nucleases for genome editing. However, mRNA's low stability and immunogenicity, as well as the impermeability of the cell membrane to mRNA greatly limit mRNA's potential for therapeutic use. Lipid nanoparticles (LNPs) are currently one of the most extensively studied nanocarriers for mRNA delivery and have recently been clinically approved for developing mRNA-based vaccines to prevent COVID-19. In this review, we summarize the latest advances in designing ionizable lipids and formulating LNPs for intracellular and tissue-targeted mRNA delivery. Furthermore, we discuss the progress of intracellular mRNA delivery for spatiotemporally controlled CRISPR/Cas9 genome editing by using LNPs. Finally, we provide a perspective on the future of LNP-based mRNA delivery for CRISPR/Cas9 genome editing and the treatment of genetic disorders.

Bilateral cardiac sympathetic denervation in patients with congenital long QT syndrome

Long QT syndrome (LQTS) is a potentially lethal yet treatable genetic heart disease for which left cardiac sympathetic denervation (LCSD) is a class I recommendation. Recent reports have suggested bilateral cardiac sympathetic denervation (BiCSD) as the initial surgical denervation therapy in LQTS. The purpose of this study was to determine the frequency and settings in which BiCSD was used in a tertiary referral center with expertise in LCSD. We performed a retrospective review of 234 out of 1638 patients with LQTS who underwent sympathetic denervation (14%) at our institution to identify the subset of patients who underwent BiCSD. Cardiac events (CEs) before LCSD, after LCSD, and after the completion of BiCSD were recorded and defined as being an appropriate implantable cardioverter-defibrillator shock, arrhythmic syncope, or sudden cardiac arrest. Only 11 patients (4.7%; 6 females [55%]) had BiCSD at our institution. Patients who received BiCSD trended toward being younger at diagnosis (6 ± 15 years vs 14 ± 13 years; P = .06) and being more likely to be symptomatic (73% vs 53%; P = .07) than the larger LCSD-only cohort. Continued CEs post-LCSD (3.8 CEs per patient on average) was the predominant determinant to return for BiCSD. Over 60 combined years of follow-up, 4 patients have not had a CE post-BiCSD while the other 7 patients average 3.6 nonlethal CEs. Less than 5% of all patients receiving denervation therapy underwent BiCSD. When BiCSD was chosen, it was almost always done in a staged sequential manner beginning with LCSD first and when driven by the arrhythmogenicity of the LQTS substrate, despite otherwise optimized guideline-directed therapies.

Chemo-enzymatic Synthesis of Pseudo-trisaccharide Aminoglycoside Antibiotics with Enhanced Nonsense Read-through Inducer Activity.

Aminoglycosides (AGs) are broad-spectrum antibiotics used to treat bacterial infections. Over the last two decades, studies have reported the potential of AGs in the treatment of genetic disorders caused by nonsense mutations, owing to their ability to induce the ribosomes to read through these mutations and produce a full-length protein. However, the principal limitation in the clinical application of AGs arises from their high toxicity, including nephrotoxicity and ototoxicity. In this study, five novel pseudo-trisaccharide analogs were synthesized by chemo-enzymatic synthesis by acid hydrolysis of commercially available AGs, followed by an enzymatic reaction using recombinant substrate-flexible KanM2 glycosyltransferase. The relationships between their structures and biological activities, including the antibacterial, nephrotoxic, and nonsense readthrough inducer (NRI) activities, were investigated. The absence of 1-N-acylation, 3',4'-dideoxygenation, and post-glycosyl transfer modifications on the third sugar moiety of AGs diminishes their antibacterial activities. The 3',4'-dihydroxy and 6'-hydroxy moieties regulate the in vitro nephrotoxicity of AGs in mammalian cell lines. The 3',4'-dihydroxy and 6'-methyl scaffolds are indispensable for the ex vivo NRI activity of AGs. Based on the alleviated in vitro antibacterial properties and nephrotoxicity, and the highest ex vivo NRI activity among the five compounds, a kanamycin analog (6'-methyl-3''-deamino-3''-hydroxykanamycin C) was selected as a novel AG hit for further studies on human genetic disorders caused by premature transcriptional termination.

PO-656-07 BILATERAL CARDIAC SYMPATHETIC DENERVATION IN PATIENTS WITH CONGENITAL LONG QT SYNDROME

Long QT syndrome (LQTS) is a potentially lethal, yet treatable genetic heart disease for which left cardiac sympathetic denervation (LCSD) is a class I recommendation by the ACC, AHA, and HRS as either a treatment intensifier for severe disease or a treatment alternative for side effects to standard drug therapy. Recent reports suggest bilateral CSD (BiCSD) as the initial surgical denervation therapy in LQTS.

A Treatable Genetic Disease Caused by CAD Mutation.

Type 50 early infantile epileptic encephalopathy, or EIEE-50 for short, is an autosomal recessive genetic disorder resulting from CAD mutations. So far, little has been reported on the disease. In this article, we will discuss the case of a male infant who is 8 years and 5 months old. A whole-exome sequencing of the boy revealed CAD compound heterozygous mutations. He suffered from global developmental delay and regression, refractory epilepsy, and anemia. After his diagnosis, we used uridine treatment and gained encouraging results. In this article, we will analyze our case studies in the context of the literature, so as to improve pediatricians' understanding of the disease.

Recombinant coagulation factors and their use in clinical practice

As is known, fresh frozen donor plasma is a blood component, which includes thermolabile and thermostable coagulation factors. Indications for transfusion of fresh frozen plasma are conditions in which there is a deficiency of plasma coagulation factors — bleeding, overdose of indirect anticoagulants, disseminated intravascular coagulation syndrome in the hypocoagulation phase. However, there are conditions not caused by the deficiency of all clotting factors, but associated with a lack of any link. These conditions include the most common congenital hemophilia A (factor VIII deficiency) and hemophilia B associated with factor IX deficiency, von Willebrand disease, as well as rare coagulopathy caused by a deficiency of other coagulation factors (proaccelerin, proconvertin, factor XI, fibrinogen). In such situations, it is more appropriate to replace the missing blood factors with drugs obtained from donor plasma (plasma coagulation factors) or obtained by genetic engineering (recombinant coagulation factors). Recombinant coagulation factors (RCFs) are lyophilized preparations of glycoproteins that have the biological activity of a blood coagulation factor isolated from plasma and are intended for replacement therapy in diseases associated with disorders of the blood coagulation system. The use of recombinant coagulation factors, unlike plasma ones, completely eliminates the risk of transmission of bloodborne infections, and also makes it possible to establish production regardless of the presence or absence of donor plasma reserves. The development, production and use of recombinant coagulation factors is a completely new step in the development of hematology and the treatment of hereditary diseases, which include congenital coagulopathy.

Rare treatable genetic diseases: Considering disorders with specific treatment based on molecular pathology

Rare treatable genetic diseases: Considering disorders with specific treatment based on molecular pathology