Orphan or Rare Diseases

Retrograde Cricopharyngeus Dysfunction (R-CPD): An Orphan Disease?

Tue, 2022-08-16 06:00

Am J Gastroenterol. 2022 Jun 20. doi: 10.14309/ajg.0000000000001888. Online ahead of print.

NO ABSTRACT

PMID:35973172 | DOI:10.14309/ajg.0000000000001888

Categories: Literature Watch

Quantitative electroencephalographic analysis as a potential biomarker of response to treatment with cannabidiol

Sat, 2022-08-13 06:00

Epilepsy Res. 2022 Aug 7;185:106996. doi: 10.1016/j.eplepsyres.2022.106996. Online ahead of print.

ABSTRACT

PURPOSE: Pharmaceutical grade cannabidiol (CBD) is one of the newest anti-seizure medications for refractory epilepsy, and the effects of CBD on EEG have not been fully described.

METHODS: Patients enrolled in a CBD expanded access study had EEGs prior to and 12 weeks after initiation of CBD treatment for their refractory epilepsy. In addition to evaluating the clinical EEG reports, a nonbiased quantitative EEG (qEEG) analysis of background EEG was performed to determine whether consistent changes occur in the EEG in response to administration of CBD.

RESULTS: No significant qualitative changes were seen, nor changes in quantitative markers of EEG amplitude (RMS amplitude, standard deviation of the amplitude, skewness, or kurtosis), frequency (relative delta, theta, or alpha power), Spearman correlation, or coherence between brain regions. However, relative beta power and 1/f slope, a measure of signal noise increased with the addition of CBD. When patients were separated into responders and nonresponders based on seizure reduction with CBD, responders also had decreased Spearman correlation between the frontopolar and occipital regions after addition of CBD, suggesting that responders may have quantitatively improved EEG background organization after CBD initiation. The differences in beta and 1/f slope were also seen more robustly in CBD responders compared with nonresponders after CBD initiation. These differences disappeared when analyzing only patients not taking benzodiazepines, suggesting that the effect of CBD on seizures was related to the ability of the brain to further increase beta in response to CBD in patients already taking benzodiazepines. We noted that even before initiation of CBD, 1/f slope was also significantly different in responders compared to nonresponders. Therefore, to explore the baseline EEG in responders and nonresponders, we utilized a variable selection procedure to identify baseline EEG features that could predict whether a patient's seizures would improve with CBD. In the optimal multivariable logistic model, baseline coherence, Spearman correlation, and patient sex jointly predicted whether a patient in this cohort would respond to CBD (defined as a seizure reduction of 40% or greater) with 74% accuracy. This model performed less well on a data set of reduced duration and variability, highlighting the importance of real-world testing of any clinically relevant model.

CONCLUSION: These results suggest that there are subtle changes in certain metrics detected by qEEG even at baseline that may not be perceived during qualitative EEG analysis and that could be used in the future as a biomarker to predict a patient's clinical response to CBD administration. Development of such a predictive EEG biomarker, especially before the initiation of a medication trial, could reduce unnecessary ASM exposure and improve outcomes for patients with epilepsy facing new medication selection.

PMID:35963151 | DOI:10.1016/j.eplepsyres.2022.106996

Categories: Literature Watch

Analysis of VOCs in Urine Samples Directed towards of Bladder Cancer Detection

Fri, 2022-08-12 06:00

Molecules. 2022 Aug 7;27(15):5023. doi: 10.3390/molecules27155023.

ABSTRACT

Bladder cancer is one of most common types of cancer diagnosed in the genitourinary tract. Typical tests are costly and characterized by low sensitivity, which contributes to a growing interest in volatile biomarkers. Head space solid phase microextraction (SPME) was applied for the extraction of volatile organic compounds from urine samples, and gas chromatography time of flight mass spectrometry (GC×GC TOF MS) was used for the separation and detection of urinary volatiles. A cohort of 40 adult patients with bladder cancer and 57 healthy persons was recruited. Different VOC profiles were obtained for urine samples taken from each group. Twelvecompounds were found only in the samples from theBC group.The proposed candidate biomarkers are butyrolactone; 2-methoxyphenol; 3-methoxy-5-methylphenol; 1-(2,6,6-trimethylcyclohexa-1,3-dien-1-yl)-2-buten-1-one; nootkatone and 1-(2,6,6-trimethyl-1-cyclohexenyl)-2-buten-1-one.Since most of the studies published in the field are proving the potential of VOCs detected in urine samples for the screening and discrimination of patients with bladder cancer from healthy, but rarely presenting the identity of proposed biomarkers, our study represents a novel approach.

PMID:35956972 | PMC:PMC9370153 | DOI:10.3390/molecules27155023

Categories: Literature Watch

A Novel Cell-Based Model for a Rare Disease: The Tks4-KO Human Embryonic Stem Cell Line as a Frank-Ter Haar Syndrome Model System

Fri, 2022-08-12 06:00

Int J Mol Sci. 2022 Aug 8;23(15):8803. doi: 10.3390/ijms23158803.

ABSTRACT

Tyrosine kinase substrate with four SH3 domains (Tks4) scaffold protein plays roles in cell migration and podosome formation and regulates systemic mechanisms such as adult bone homeostasis and adipogenesis. Mutations in the Tks4 gene (SH3PXD2b) cause a rare developmental disorder called Frank-Ter Haar syndrome (FTHS), which leads to heart abnormalities, bone tissue defects, and reduced adiposity. We aimed to produce a human stem cell-based in vitro FTHS model system to study the effects of the loss of the Tks4 protein in different cell lineages and the accompanying effects on the cell signalome. To this end, we used CRISPR/Cas9 (clustered, regularly interspaced, short palindromic repeats (CRISPR)/CRISPR associated (Cas9)) to knock out the SH3PXD2b gene in the HUES9 human embryonic stem cell line (hESC), and we obtained stable homo- and heterozygous knock out clones for use in studying the potential regulatory roles of Tks4 protein in embryonic stem cell biology. Based on pluripotency marker measurements and spontaneous differentiation capacity assays, we concluded that the newly generated Tks4-KO HUES9 cells retained their embryonic stem cell characteristics. We propose that the Tks4-KO HUES9 cells could serve as a tool for further cell differentiation studies to investigate the involvement of Tks4 in the complex disorder FTHS. Moreover, we successfully differentiated all of the clones into mesenchymal stem cells (MSCs). The derived MSC cultures showed mesenchymal morphology and expressed MSC markers, although the expression levels of mesodermal and osteogenic marker genes were reduced, and several EMT (epithelial mesenchymal transition)-related features were altered in the Tks4-KO MSCs. Our results suggest that the loss of Tks4 leads to FTHS by altering cell lineage differentiation and cell maturation processes, rather than by regulating embryonic stem cell potential.

PMID:35955935 | PMC:PMC9369304 | DOI:10.3390/ijms23158803

Categories: Literature Watch

Systematic Review: Drug Repositioning for Congenital Disorders of Glycosylation (CDG)

Fri, 2022-08-12 06:00

Int J Mol Sci. 2022 Aug 5;23(15):8725. doi: 10.3390/ijms23158725.

ABSTRACT

Advances in research have boosted therapy development for congenital disorders of glycosylation (CDG), a group of rare genetic disorders affecting protein and lipid glycosylation and glycosylphosphatidylinositol anchor biosynthesis. The (re)use of known drugs for novel medical purposes, known as drug repositioning, is growing for both common and rare disorders. The latest innovation concerns the rational search for repositioned molecules which also benefits from artificial intelligence (AI). Compared to traditional methods, drug repositioning accelerates the overall drug discovery process while saving costs. This is particularly valuable for rare diseases. AI tools have proven their worth in diagnosis, in disease classification and characterization, and ultimately in therapy discovery in rare diseases. The availability of biomarkers and reliable disease models is critical for research and development of new drugs, especially for rare and heterogeneous diseases such as CDG. This work reviews the literature related to repositioned drugs for CDG, discovered by serendipity or through a systemic approach. Recent advances in biomarkers and disease models are also outlined as well as stakeholders' views on AI for therapy discovery in CDG.

PMID:35955863 | PMC:PMC9369176 | DOI:10.3390/ijms23158725

Categories: Literature Watch

Role of surgery to the primary tumor in metastatic anaplastic thyroid carcinoma: pooled analysis and SEER-based study

Fri, 2022-08-12 06:00

J Cancer Res Clin Oncol. 2022 Aug 12. doi: 10.1007/s00432-022-04223-7. Online ahead of print.

ABSTRACT

PURPOSE: Anaplastic thyroid carcinoma (ATC) is an orphan disease with a fatal outcome. Surgery to the primary tumor in metastatic ATC is controversial. Determination of specific surgical techniques may help facilitate local control and, hence, beneficial overall and disease-specific survival.

METHODS: Using individualized patient data derived from our systematic review of literature and our single center study (n = 123), conducting a Surveillance, Epidemiology, and End Results register (SEER)-based study (n = 617) we evaluated surgery, its combination with systemic and local therapies in metastatic ATC.

RESULTS: Pooled cohort study showed surgery (p < 0.001), RT ≥ 30 Gy (p < 0.001), ChT (p < 0.001) and multimodal treatment (p = 0.014) to result in improved OS univariately. In the multivariate analysis, surgery (1.997 [1.162-3.433], p = 0.012) and RT ≥ 30 Gy (1.877 [1.232-2.843], p = 0.012) were independent predictors for OS. In SEER-based study of patients undergoing any tumor-directed treatment (n = 445) total thyroidectomy (p = 0.031), administration of ChT (p = 0.007), RT (p < 0.001), combination of surgery and RT ± ChT (p < 0.001) and multimodal treatment (p < 0.001) correlated with an improved DSS univariately. On the multivariate analysis, debulking surgery was an independent predictor for a worse outcome (HR 0.535, 95%CI 0.332-0.862, p = 0.010), whereas RT administration correlated with a longer DSS (HR 2.316, 95%CI 1.362-3.939, p = 0.002). Among operated patients from SEER register total thyroidectomy (p = 0.031), ChT (p = 0.007), RT (p < 0.001), combination of surgery and RT ± ChT (p < 0.001) and multimodal treatment (p < 0.001) correlated with an improved DSS in the univariate analysis, whereas debulking surgery was inversely correlated with the DSS (p < 0.001). On the multivariate analysis, debulking surgery was an independent predictor for a worse DSS (HR 0.535, 95%CI 0.332-0.862, p = 0.010), whilst RT administration correlated with a longer DSS (HR 2.316, 95%CI 1.362-3.939, p = 0.002).

CONCLUSIONS: Surgery to the primary tumor with the aim of R0/R1 resection, but not debulking, is associated with a significant OS and DSS benefit even in systemically metastasized disease.

PMID:35960373 | DOI:10.1007/s00432-022-04223-7

Categories: Literature Watch

Monomelic amyotrophy: a rare disease with unusual features (Hirayama disease)

Thu, 2022-08-11 06:00

Pan Afr Med J. 2022 May 18;42:48. doi: 10.11604/pamj.2022.42.48.29515. eCollection 2022.

NO ABSTRACT

PMID:35949470 | PMC:PMC9338714 | DOI:10.11604/pamj.2022.42.48.29515

Categories: Literature Watch

The next generation of rare disease drug policy: ensuring both innovation and affordability

Wed, 2022-08-10 06:00

J Comp Eff Res. 2022 Oct;11(14):999-1010. doi: 10.2217/cer-2022-0120. Epub 2022 Aug 10.

ABSTRACT

Scientific advancements, new US FDA approval pathways and limited competition have contributed to rapid growth in the number of approved rare disease treatments in recent years. While the rising numbers of orphan drug approvals are a sign of success, the rapid growth in approved rare disease treatments has created concerns about the pricing of orphan drugs and their cumulative affordability to the health system. To support efforts to build a policy and practice infrastructure that drives innovation within a platform that is affordable to patients and the health system, this paper provides an analysis of potential risks as well as advantages of reform options related to drug development, pricing and coverage.

PMID:35946484 | DOI:10.2217/cer-2022-0120

Categories: Literature Watch

Quality of Life and Physical Activity in 629 Individuals With Sarcoidosis: Prospective, Cross-sectional Study Using Smartphones (Sarcoidosis App)

Wed, 2022-08-10 06:00

JMIR Mhealth Uhealth. 2022 Aug 10;10(8):e38331. doi: 10.2196/38331.

ABSTRACT

BACKGROUND: Large gaps exist in understanding the symptomatic and functional impact of sarcoidosis, a rare multisystem granulomatous disease affecting fewer than 200,000 individuals in the United States. Smartphones could be used for prospective research, especially for rare diseases where organizing large cohorts can be challenging, given their near ubiquitous ownership and ability to track objective and subjective data with increasingly sophisticated technology.

OBJECTIVE: We aimed to investigate whether smartphones could assess the quality of life (QoL) and physical activity of a large cohort of individuals with sarcoidosis.

METHODS: We developed a mobile app (Sarcoidosis App) for a prospective, cross-sectional study on individuals with sarcoidosis. The Sarcoidosis App was made available on both Apple and Android smartphones. Individuals with sarcoidosis were recruited, consented, and enrolled entirely within the app. Surveys on sarcoidosis history, medical history, and medications were administered. Patients completed modules from the Sarcoidosis Assessment Tool, a validated patient-reported outcomes assessment of physical activity, fatigue, pain, skin symptoms, sleep, and lungs symptoms. Physical activity measured by smartphones was tracked as available.

RESULTS: From April 2018 to May 2020, the App was downloaded 2558 times, and 629 individuals enrolled (404, 64.2% female; mean age 51 years; 513, 81.6% White; 86, 13.7% Black). Two-thirds of participants had a college or graduate degree, and more than half of them reported an income greater than US $60,000. Both QoL related to physical activity (P<.001, ρ=0.250) and fatigue (P<.01, ρ=-0.203) correlated with actual smartphone-tracked physical activity. Overall, 19.0% (98/517) of participants missed at least 1 week of school or work in an observed month owing to sarcoidosis, and 44.4% (279/629) reported that finances "greatly" or "severely" affected by sarcoidosis. Furthermore, 71.2% (437/614) of participants reported taking medications for sarcoidosis, with the most common being prednisone, methotrexate, hydroxychloroquine, and infliximab. Moreover, 46.4% (244/526) reported medication side effects, most commonly due to prednisone.

CONCLUSIONS: We demonstrate that smartphones can prospectively recruit, consent, and study physical activity, QoL, and medication usage in a large sarcoidosis cohort, using both passively collected objective data and qualitative surveys that did not require any in-person encounters. Our study's limitations include the study population being weighted toward more educated and wealthier individuals, suggesting that recruitment was not representative of the full spectrum of patients with sarcoidosis in the United States. Our study provides a model for future smartphone-enabled clinical research for rare diseases and highlights key technical challenges that future research teams interested in smartphone-based research for rare diseases should anticipate.

PMID:35947439 | DOI:10.2196/38331

Categories: Literature Watch

Enhanced rare disease mapping for phenome-wide genetic association in the UK Biobank

Tue, 2022-08-09 06:00

Genome Med. 2022 Aug 9;14(1):85. doi: 10.1186/s13073-022-01094-y.

ABSTRACT

BACKGROUND: Rare diseases collectively affect up to 10% of the population, but often lack effective treatment, and typically little is known about their pathophysiology. Major challenges include suboptimal phenotype mapping and limited statistical power. Population biobanks, such as the UK Biobank, recruit many individuals who can be affected by rare diseases; however, investigation into their utility for rare disease research remains limited. We hypothesized the UK Biobank can be used as a unique population assay for rare diseases in the general population.

METHODS: We constructed a consensus mapping between ICD-10 codes and ORPHA codes for rare diseases, then identified individuals with each rare condition in the UK Biobank, and investigated their age at recruitment, sex bias, and comorbidity distributions. Using exome sequencing data from 167,246 individuals of European ancestry, we performed genetic association controlling for case/control imbalance (SAIGE) to identify potential rare pathogenic variants for each disease.

RESULTS: Using our mapping approach, we identified and characterized 420 rare diseases affecting 23,575 individuals in the UK Biobank. Significant genetic associations included JAK2 V617F for immune thrombocytopenic purpura (p = 1.24 × 10-13) and a novel CALR loss of function variant for essential thrombocythemia (p = 1.59 × 10-13). We constructed an interactive resource highlighting demographic information ( http://www-personal.umich.edu/~mattpat/rareDiseases.html ) and demonstrate transferability by applying our mapping to a medical claims database.

CONCLUSIONS: Enhanced disease mapping and increased power from population biobanks can elucidate the demographics and genetic associations for rare diseases.

PMID:35945607 | DOI:10.1186/s13073-022-01094-y

Categories: Literature Watch

Inflammatory diseases in hematology: a review

Mon, 2022-08-08 06:00

Am J Physiol Cell Physiol. 2022 Aug 8. doi: 10.1152/ajpcell.00356.2021. Online ahead of print.

ABSTRACT

Hematopoietic cells are instrumental in generating and propagating protective inflammatory responses to infection or injury. However, excessive inflammation contributes to many diseases of the blood, bone marrow, and lymphatic system. We review three clinical categories of hematological inflammatory diseases in which recent clinical and translational advances have been made. The first category are monogenic inflammatory diseases. Genotype-driven research has revealed that previously mysterious diseases with protean manifestations are characterized by mutations which may be germline (e.g. deficiency of ADA2 or GATA2 deficiency) or somatic (e.g. VEXAS syndrome). The second category are the cytokine storm syndromes, including hemophagocytic lymphohistiocytosis and Castleman disease. Cytokine storm syndromes are characterized by excessive production of inflammatory cytokines including interleukin-6 and interferon-gamma, causing end-organ damage and high mortality. Finally, we review disorders associated with monoclonal and polyclonal hypergammaglobulinemia. The serum protein electrophoresis (SPEP) is typically ordered to screen for common diseases such as myeloma and humoral immunodeficiency. However, monoclonal and polyclonal hypergammaglobulinemia on SPEP can also provide important information in rare inflammatory diseases. For example, the autoinflammatory disease Schnitzler syndrome is notoriously difficult to diagnose. While this orphan disease has eluded precise genetic or histological characterization, the presence of a monoclonal paraprotein, typically IgM, is an obligate diagnostic criterion. Likewise, polyclonal hypergammaglobulinemia may be an important early, non-invasive diagnostic clue for patients presenting with rare neoplastic diseases such as Rosai-Dorfman disease and angioimmunoblastic T-cell lymphoma. Applying these three categories to patients with unexplained inflammatory syndromes can facilitate the diagnosis of rare and under-recognized diseases.

PMID:35938681 | DOI:10.1152/ajpcell.00356.2021

Categories: Literature Watch

Coincidence of pachydermoperiostosis and synovitis, acne, pustulosis, hyperostosis, osteitis syndrome, a causal or casual association?

Mon, 2022-08-08 06:00

Int J Rheum Dis. 2022 Aug 8. doi: 10.1111/1756-185X.14418. Online ahead of print.

ABSTRACT

Pachydermoperiostosis (PDP) is a rare disorder characterized by skin thickening, acropachia, and periostosis. Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome is also an orphan disease featured by different dermatological and osteoarthritic manifestations. Herein, we report the first case of an adolescent male diagnosed with both PDP and SAPHO syndrome, presenting with digital clubbing, polyarthralgia, ostealgia, pachydermia and acne on his face, chest and back. Furthermore, we distinguish the characteristics of both diseases and explore the potential pathological mechanism for this coexistence in one patient. Further investigations are needed to establish the detailed pathophysiological association of these 2 diseases.

PMID:35938529 | DOI:10.1111/1756-185X.14418

Categories: Literature Watch

Patient involvement in priority-setting for medical research: A mini review of initiatives in the rare disease field

Fri, 2022-08-05 06:00

Front Public Health. 2022 Jul 19;10:915438. doi: 10.3389/fpubh.2022.915438. eCollection 2022.

ABSTRACT

Patient involvement (PI) in determining medical research priorities is an important way to ensure that limited research funds are allocated to best serve patients. As a disease area for which research funds are limited, we see a particular utility for PI in priority-setting for medical research on rare diseases. In this review, we argue that PI initiatives are an important form of evidence for policymaking. We conducted a study to identify the extent to which PI initiatives are being conducted in the rare disease field, the features of such initiatives, the trends in the priorities elicited, and the extent to which translation into policy is reported in the academic literature. Here, we report the results of this exploratory review of the English-language literature gathered through online databases and search engines, with the aim of identifying journal articles published prior to December 2020, describing PI initiatives focused on determining priorities for medical research funding in the rare disease field. We identified seven recently-published articles and found that the majority made use of structured methodologies to ensure the robustness of the evidence produced, but found little reported practical implementation or concrete plans for implementation of the results of the initiatives. We conclude that priority-setting initiatives are meaningful mechanisms for involving patients in determining research directions. However, we highlight the importance of translation into policy as a necessary next step to fully utilize the results and move beyond well-intentioned exercises. Finally, we draw attention to the benefits of involving patients throughout this process.

PMID:35928485 | PMC:PMC9343727 | DOI:10.3389/fpubh.2022.915438

Categories: Literature Watch

Systems biochemistry to "deorphanize" human mitochondrial proteome

Fri, 2022-08-05 06:00

Mol Cell. 2022 Aug 4;82(15):2735-2737. doi: 10.1016/j.molcel.2022.07.005.

ABSTRACT

Rensvold, Shishkova, et al. (2022) apply an integrated systems biology approach spanning proteomics, lipidomics, and metabolomics to a collection of CRISPR knockout cells targeting 116 distinct human mitochondrial proteins, revealing new mitochondrial biology and guiding orphan disease diagnosis.

PMID:35931038 | DOI:10.1016/j.molcel.2022.07.005

Categories: Literature Watch

Potency of the novel PolC DNA polymerase inhibitor CRS0540 in a disseminated Listeria monocytogenes intracellular hollow-fibre model

Fri, 2022-08-05 06:00

J Antimicrob Chemother. 2022 Aug 5:dkac269. doi: 10.1093/jac/dkac269. Online ahead of print.

ABSTRACT

BACKGROUND: Listeriosis is an orphan disease, which is nevertheless fatal in immunocompromised people. CRS0540 is a novel PolC DNA polymerase inhibitor that has demonstrated good in vitro and in vivo activity against Listeria monocytogenes.

METHODS: Rodent-to-human allometry projection-based human population pharmacokinetics of CRS0540 were used for all studies. CRS0540 pharmacokinetics/pharmacodynamics studies in an intracellular hollow-fibre system model of disseminated listeriosis (HFS-Lister) examined the effect of eight treatment doses, administered daily over 7 days, in duplicate units. Total bacterial burden versus AUC/MIC exposures on each day were modelled using the inhibitory sigmoid Emax model, while CRS0540-resistant bacterial burden was modelled using a quadratic function. Ten thousand-subject Monte Carlo simulations were used to predict an optimal clinical dose for treatment.

RESULTS: The mean CRS0540 intracellular/extracellular AUC0-24 ratio was 34.07 (standard error: 15.70) as measured in the HFS-Lister. CRS0540 demonstrated exposure-dependent bactericidal activity in the HFS-Lister, with the highest exposure killing approximately 5.0 log10 cfu/mL. The free drug AUC0-24/MIC associated with 80% of maximal kill (EC80) was 36.4. Resistance emergence versus AUC/MIC was described by a quadratic function, with resistance amplification at an AUC/MIC of 54.8 and resistance suppression at an AUC/MIC of 119. Monte Carlo simulations demonstrated that for the EC80 target, IV CRS0540 doses of 100 mg/kg achieved PTAs of >90% at MICs up to 1.0 mg/L.

CONCLUSIONS: CRS0540 is a promising orphan drug candidate for listeriosis. Future PK/PD studies comparing it with penicillin, the standard of care, could lead to this drug as a new treatment in immunocompromised patients.

PMID:35929190 | DOI:10.1093/jac/dkac269

Categories: Literature Watch

ZSE-DUO - dual guidance structure at the centre for rare diseases

Thu, 2022-08-04 06:00

Inn Med (Heidelb). 2022 Jul;63(7):791-797. doi: 10.1007/s00108-022-01350-8. Epub 2022 Jun 2.

ABSTRACT

BACKGROUND: Patients with an unclear diagnosis and suspected rare disease pose special challenges to physicians, among others.

AIM OF THE STUDY (RESEARCH QUESTION): The ZSE-DUO project aims to establish whether patient care under the joint supervision of a somatic expert and a mental health expert can improve diagnostic efficacy and precision, as well as shorten the time to diagnosis.

MATERIAL AND METHODS: ZSE-DUO has successfully recruited more than 1000 patients at eleven national centres for rare diseases in a control and an intervention group. The findings are being analysed by three evaluating institutions.

RESULTS AND DISCUSSION: The study is currently in its final phase. The results will be published in further papers.

PMID:35925266 | DOI:10.1007/s00108-022-01350-8

Categories: Literature Watch

De novo variants cause complex symptoms in HSP-ATL1 (SPG3A) and uncover genotype-phenotype correlations

Thu, 2022-08-04 06:00

Hum Mol Genet. 2022 Aug 4:ddac182. doi: 10.1093/hmg/ddac182. Online ahead of print.

ABSTRACT

Pathogenic variants in ATL1 are a known cause of autosomal-dominantly inherited hereditary spastic paraplegia (HSP-ATL1, SPG3A) with a predominantly 'pure' HSP phenotype. Although a relatively large number of patients have been reported, no genotype-phenotype correlations have been established for specific ATL1 variants. Confronted with five children carrying de novo ATL1 variants showing early, complex and severe symptoms, we systematically investigated the molecular and phenotypic spectrum of HSP-ATL1. Through a cross-sectional analysis of 537 published and novel cases, we delineate a distinct phenotype observed in patients with de novo variants. Guided by this systematic phenotyping approach and structural modelling of disease-associated variants in atlastin-1, we demonstrate that this distinct phenotypic signature is also prevalent in a subgroup of patients with inherited ATL1 variants and is largely explained by variant localization within a three-dimensional mutational cluster. Establishing genotype-phenotype correlations, we find that symptoms that extend well beyond the typical pure HSP phenotype (i.e. neurodevelopmental abnormalities, upper limb spasticity, bulbar symptoms, peripheral neuropathy and brain imaging abnormalities) are prevalent in patients with variants located within this mutational cluster.

PMID:35925862 | DOI:10.1093/hmg/ddac182

Categories: Literature Watch

Ethical implications of early genetic diagnosis in an infant with Lesch-Nyhan syndrome

Tue, 2022-08-02 06:00

J Genet Couns. 2022 Aug 2. doi: 10.1002/jgc4.1616. Online ahead of print.

ABSTRACT

Pathogenic variants in HPRT1 lead to deficiency in hypoxanthine-guanine phosphoribosyltransferase and are responsible for a spectrum of disorders. The severe phenotype is termed Lesch-Nyhan syndrome (LNS) and is inherited in an X-linked recessive manner. Most individuals with LNS have profound intellectual and physical disabilities throughout life including self-mutilating behaviors. Here, we present the case of a male infant who was diagnosed with LNS at 3 weeks of age via rapid exome sequencing (ES), which revealed a hemizygous maternally inherited deletion of at least 1.3 Mb of Xq26.3, including exons 2 to 9 of HPRT1. We discuss the critical time points leading to this diagnosis while highlighting his parents' values that guided the decision-making. Genetic testing provided an early diagnosis for this infant that led to important considerations regarding goals of care in addition to raising new ethical concerns. This highlights the important role that early and rapid diagnostic genetic testing can play in helping families make difficult decisions. Additionally, this case highlights the complexity of discussing rare genetic diagnoses with families and facilitating critical discussions to empower the family toward making an informed decision.

PMID:35916015 | DOI:10.1002/jgc4.1616

Categories: Literature Watch

Bladder Cancer Patient-derived Organoids and Avatars for Personalized Cancer Discovery

Mon, 2022-08-01 06:00

Eur Urol Focus. 2022 May;8(3):657-659. doi: 10.1016/j.euf.2022.07.006. Epub 2022 Jul 30.

ABSTRACT

Prediction of treatment response has attracted growing attention in cancer research to improve clinical outcomes via individualized treatment regimens. Patient-derived organoids and xenografts are novel preclinical model systems that recapitulate the genetic and phenotypic features of parental tumors for this purpose. Organoid culture has been successfully established in multiple cancers and used for assessment of drug and immunotherapy responses. Patient-derived xenograft (PDX) models provide insights into in vivo tumor growth and metastatic potential. Continued improvements in these model systems to better maintain tumor architecture and microenvironment will advance patient-specific targeted therapies. PATIENT SUMMARY: This mini review describes up-to-date organoid and xenograft models of bladder cancer created using patient-derived tissue. These models are important for research and may provide information on mutations and expression patterns for cancer-related genes that are unique to each patient, and could facilitate personalized therapy for individual patients.

PMID:35915037 | DOI:10.1016/j.euf.2022.07.006

Categories: Literature Watch

The predictive value of models of neuromuscular disorders to potentiate clinical translation

Mon, 2022-08-01 06:00

Dis Model Mech. 2022 Jul 1;15(7):dmm049788. doi: 10.1242/dmm.049788. Epub 2022 Aug 1.

ABSTRACT

Neuromuscular disorders (NMDs) are a heterogenous group of rare inherited diseases that compromise the function of peripheral nerves and/or muscles. With limited treatment options available, there is a growing need to design effective preclinical studies that can lead to greater success in clinical trials for novel therapeutics. Here, I discuss recent advances in modelling NMDs to improve preclinical studies as well as two articles from this issue that work in parallel to enable a deeper understanding of a particularly rare NMD, known as X-linked myotubular myopathy.

PMID:35912512 | DOI:10.1242/dmm.049788

Categories: Literature Watch

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