Orphan or Rare Diseases
[Anesthetic management of two patients with alkaptonuric ochronosis for total knee arthroplasty].
[Anesthetic management of two patients with alkaptonuric ochronosis for total knee arthroplasty].
Rev Bras Anestesiol. 2017 May 20;:
Authors: Kozanhan B
Abstract
The current case report describes two cases of alkaptonuric ochronosis for anesthetic management. Alkaptonuria is a rare genetic orphan disease of tyrosine metabolism characterized by an accumulation of homogentisic acid in cartilage and connective tissues. Patients present most commonly for orthopedic joint surgery due to progressive arthropathy that can be misdiagnosed many a times. However respiratory, airway, cardiovascular and genitourinary systems complications can occur with age progressing. Restricted range of motion of cervical spine may lead to difficulty with airway management. In addition, degenerative changes and stiffness of lumbar spine due to ochronosis would make neuraxial blockade challenging. Although this inherited condition is extremely rare, anesthesiologists should be aware of its existence and prepare for management of potential challenging problems. This report highlights special care and precautions that need to be taken during anesthetic management.
PMID: 28535941 [PubMed - as supplied by publisher]
Comprehensive Rare Variant Analysis via Whole-Genome Sequencing to Determine the Molecular Pathology of Inherited Retinal Disease.
Comprehensive Rare Variant Analysis via Whole-Genome Sequencing to Determine the Molecular Pathology of Inherited Retinal Disease.
Am J Hum Genet. 2017 01 05;100(1):75-90
Authors: Carss KJ, Arno G, Erwood M, Stephens J, Sanchis-Juan A, Hull S, Megy K, Grozeva D, Dewhurst E, Malka S, Plagnol V, Penkett C, Stirrups K, Rizzo R, Wright G, Josifova D, Bitner-Glindzicz M, Scott RH, Clement E, Allen L, Armstrong R, Brady AF, Carmichael J, Chitre M, Henderson RH, Hurst J, MacLaren RE, Murphy E, Paterson J, Rosser E, Thompson DA, Wakeling E, Ouwehand WH, Michaelides M, Moore AT, NIHR-BioResource Rare Diseases Consortium, Webster AR, Raymond FL
Abstract
Inherited retinal disease is a common cause of visual impairment and represents a highly heterogeneous group of conditions. Here, we present findings from a cohort of 722 individuals with inherited retinal disease, who have had whole-genome sequencing (n = 605), whole-exome sequencing (n = 72), or both (n = 45) performed, as part of the NIHR-BioResource Rare Diseases research study. We identified pathogenic variants (single-nucleotide variants, indels, or structural variants) for 404/722 (56%) individuals. Whole-genome sequencing gives unprecedented power to detect three categories of pathogenic variants in particular: structural variants, variants in GC-rich regions, which have significantly improved coverage compared to whole-exome sequencing, and variants in non-coding regulatory regions. In addition to previously reported pathogenic regulatory variants, we have identified a previously unreported pathogenic intronic variant in CHM in two males with choroideremia. We have also identified 19 genes not previously known to be associated with inherited retinal disease, which harbor biallelic predicted protein-truncating variants in unsolved cases. Whole-genome sequencing is an increasingly important comprehensive method with which to investigate the genetic causes of inherited retinal disease.
PMID: 28041643 [PubMed - indexed for MEDLINE]
The sensitivity of exome sequencing in identifying pathogenic mutations for LGMD in the United States.
The sensitivity of exome sequencing in identifying pathogenic mutations for LGMD in the United States.
J Hum Genet. 2017 Feb;62(2):243-252
Authors: Reddy HM, Cho KA, Lek M, Estrella E, Valkanas E, Jones MD, Mitsuhashi S, Darras BT, Amato AA, Lidov HG, Brownstein CA, Margulies DM, Yu TW, Salih MA, Kunkel LM, MacArthur DG, Kang PB
Abstract
The current study characterizes a cohort of limb-girdle muscular dystrophy (LGMD) in the United States using whole-exome sequencing. Fifty-five families affected by LGMD were recruited using an institutionally approved protocol. Exome sequencing was performed on probands and selected parental samples. Pathogenic mutations and cosegregation patterns were confirmed by Sanger sequencing. Twenty-two families (40%) had novel and previously reported pathogenic mutations, primarily in LGMD genes, and also in genes for Duchenne muscular dystrophy, facioscapulohumeral muscular dystrophy, congenital myopathy, myofibrillar myopathy, inclusion body myopathy and Pompe disease. One family was diagnosed via clinical testing. Dominant mutations were identified in COL6A1, COL6A3, FLNC, LMNA, RYR1, SMCHD1 and VCP, recessive mutations in ANO5, CAPN3, GAA, LAMA2, SGCA and SGCG, and X-linked mutations in DMD. A previously reported variant in DMD was confirmed to be benign. Exome sequencing is a powerful diagnostic tool for LGMD. Despite careful phenotypic screening, pathogenic mutations were found in other muscle disease genes, largely accounting for the increased sensitivity of exome sequencing. Our experience suggests that broad sequencing panels are useful for these analyses because of the phenotypic overlap of many neuromuscular conditions. The confirmation of a benign DMD variant illustrates the potential of exome sequencing to help determine pathogenicity.
PMID: 27708273 [PubMed - indexed for MEDLINE]
Epidemiological investigations on the potential transmissibility of a rare disease: the case of atypical scrapie in Great Britain.
Epidemiological investigations on the potential transmissibility of a rare disease: the case of atypical scrapie in Great Britain.
Epidemiol Infect. 2016 Jul;144(10):2107-16
Authors: Ortiz-Peláez A, Arnold ME, Vidal-Diez A
Abstract
Multiple cases of atypical scrapie in the same holding and co-existence with classical scrapie have been reported in Great Britain. A two-stage simulation tool was developed by combining a sampling algorithm and a hierarchical Bayesian model to simulate the number of positive cases of atypical scrapie from: (i) random sampling and (ii) using the actual sampled population in Great Britain, being the output probability of detection of flocks with one and more cases. Cluster analysis was conducted to assess the level of geographical over- and under-sampling over the years. The probability of detecting at least two cases of atypical scrapie in the same holding is much lower in simulated random data than in simulated actual data for all scenarios. Sampling bias in the selection of sheep for testing led to multiple sampling from fewer but larger holdings, Scotland, and areas of Wales were under-sampled and the South-West and East of England oversampled. The pattern of atypical scrapie cases observed is unlikely to be explained by a multi-case event epidemiologically linked. The co-existence of classical and atypical scrapie is a rare event with 19 holdings detected in GB and does not suggest an epidemiological link between the two types of disease.
PMID: 26976340 [PubMed - indexed for MEDLINE]
Repression of phosphatidylinositol transfer protein α ameliorates the pathology of Duchenne muscular dystrophy.
Repression of phosphatidylinositol transfer protein α ameliorates the pathology of Duchenne muscular dystrophy.
Proc Natl Acad Sci U S A. 2017 May 22;:
Authors: Vieira NM, Spinazzola JM, Alexander MS, Moreira YB, Kawahara G, Gibbs DE, Mead LC, Verjovski-Almeida S, Zatz M, Kunkel LM
Abstract
Duchenne muscular dystrophy (DMD) is a progressive muscle wasting disease caused by X-linked inherited mutations in the DYSTROPHIN (DMD) gene. Absence of dystrophin protein from the sarcolemma causes severe muscle degeneration, fibrosis, and inflammation, ultimately leading to cardiorespiratory failure and premature death. Although there are several promising strategies under investigation to restore dystrophin protein expression, there is currently no cure for DMD, and identification of genetic modifiers as potential targets represents an alternative therapeutic strategy. In a Brazilian golden retriever muscular dystrophy (GRMD) dog colony, two related dogs demonstrated strikingly mild dystrophic phenotypes compared with those typically observed in severely affected GRMD dogs despite lacking dystrophin. Microarray analysis of these "escaper" dogs revealed reduced expression of phosphatidylinositol transfer protein-α (PITPNA) in escaper versus severely affected GRMD dogs. Based on these findings, we decided to pursue investigation of modulation of PITPNA expression on dystrophic pathology in GRMD dogs, dystrophin-deficient sapje zebrafish, and human DMD myogenic cells. In GRMD dogs, decreased expression of Pitpna was associated with increased phosphorylated Akt (pAkt) expression and decreased PTEN levels. PITPNA knockdown by injection of morpholino oligonucleotides in sapje zebrafish also increased pAkt, rescued the abnormal muscle phenotype, and improved long-term sapje mutant survival. In DMD myotubes, PITPNA knockdown by lentiviral shRNA increased pAkt and increased myoblast fusion index. Overall, our findings suggest PIPTNA as a disease modifier that accords benefits to the abnormal signaling, morphology, and function of dystrophic skeletal muscle, and may be a target for DMD and related neuromuscular diseases.
PMID: 28533404 [PubMed - as supplied by publisher]
Progress towards generation of human haematopoietic stem cells.
Progress towards generation of human haematopoietic stem cells.
Nat Cell Biol. 2016 Nov;18(11):1111-1117
Authors: Wahlster L, Daley GQ
Abstract
De novo generation of haematopoietic stem cells from different human pluripotent stem cell sources remains a high priority for haematology and regenerative medicine. At present, efficient derivation of functional haematopoietic stem cells with the capability for definitive in vivo engraftment and multi-lineage potential remains challenging. Here, we discuss recent progress and strategies to overcome obstacles that have thwarted past efforts. In addition, we review promising advances in the generation of mature blood lineages and the potential of induced pluripotent stem cells.
PMID: 27723718 [PubMed - indexed for MEDLINE]
Development and initial validation of international severity scoring system for familial Mediterranean fever (ISSF).
Development and initial validation of international severity scoring system for familial Mediterranean fever (ISSF).
Ann Rheum Dis. 2016 Jun;75(6):1051-6
Authors: Demirkaya E, Acikel C, Hashkes P, Gattorno M, Gul A, Ozdogan H, Turker T, Karadag O, Livneh A, Ben-Chetrit E, Ozen S, FMF Arthritis Vasculitis and Orphan disease Research in pediatric rheumatology (FAVOR)
Abstract
OBJECTIVE: To develop widely accepted international severity score for children and adult patients with familial Mediterranean fever (FMF) that can be easily applied, in research and clinical practice.
METHODS: Candidate severity criteria were suggested by several FMF expert physicians. After three rounds of Delphi survey, the candidate criteria, defined by the survey, were discussed by experts in a consensus meeting. Each expert brought data of clinical manifestations, laboratory findings and physician's global assessments (PGAs) of minimum 20 patients from their centres. We used the PGAs for disease severity as a gold standard. Logistic regression analysis was used to evaluate the predicting value of each item, and receiver operating characteristic curve analysis was performed to demonstrate the success of the criteria set.
RESULTS: A total of 281 patients consist of 162 children and 119 adults with FMF were enrolled and available for validity analysis: Nine domains were included in the final core set of variables for the evaluation of disease severity in FMF. The International Severity Score for FMF (ISSF) may reach a maximum of 10 if all items are maximally scored. The threshold values to determine: severe disease ≥6, intermediate disease 3-5, mild disease ≤2. Area under the curve was calculated as 0.825 for this set in the whole group.
CONCLUSIONS: The initial validity of ISSF both in children and adult with FMF was demonstrated. We anticipate that it will provide a robust tool to objectively define disease severity for clinical trials, future research as well as for therapeutic decisions in managing patients with FMF.
PMID: 26823530 [PubMed - indexed for MEDLINE]
Finding Rare, Disease-Associated Variants in Isolated Groups: Potential Advantages of Mennonite Populations.
Finding Rare, Disease-Associated Variants in Isolated Groups: Potential Advantages of Mennonite Populations.
Hum Biol. 2016 Apr;88(2):109-120
Authors: Lopes FL, Hou L, Boldt AB, Kassem L, Alves VM, Nardi AE, McMahon FJ
Abstract
Large-scale genotyping and next-generation sequencing techniques have allowed great advances in the field of molecular genetics. Numerous common variants of low impact have been associated with many complex human traits and diseases, such as bipolar disorder and schizophrenia. Although they may exert a greater impact on risk, few rare disease variants have been found, owing to the greatly increased sample sizes that are typically necessary to demonstrate association with rarer variants. One alternative strategy is to study isolated populations, where historical bottlenecks reduce genetic diversity and some otherwise rare variants may drift to higher frequencies. Here we describe the Mennonite population settlements, considering their history of multiple bottlenecks followed by demographic expansion and a currently widespread geographical distribution. We argue that Mennonite populations are valuable partners for studies seeking genetic variants that exert a high impact on risk for a variety of common disorders, including mental illnesses.
PMID: 28162000 [PubMed - indexed for MEDLINE]
Acute anterior wall myocardial infraction in asymptomatic severe aortic Coarctation in young adult - A rare case.
Acute anterior wall myocardial infraction in asymptomatic severe aortic Coarctation in young adult - A rare case.
Indian Heart J. 2016 Jul-Aug;68(4):523-4
Authors: Singhal G, Pathak V
Abstract
Coarctation of Aorta is not rare in general population. Aortic Coarctation represents about 5-8% of all congenital cardiac diseases, and it is commonly associated with bicuspid aortic valve. Coarctation of Aorta is typically a disease of childhood and early adulthood, reducing life expectancy in patients, who have not undergone correction. Many case reports of Coarctation of Aorta patients presenting with anterior wall myocardial infraction have been published in various journals, but to the best of our knowledge, no case of Coarctation of Aorta with acute anterior wall myocardial in 30-year-old male is reported till date. We are presenting a rare case of anterior wall myocardial infraction in young male with asymptomatic Coarctation of Aorta.
PMID: 27543476 [PubMed - indexed for MEDLINE]
Pre-referral GP consultations in patients subsequently diagnosed with rarer cancers: a study of patient-reported data.
Pre-referral GP consultations in patients subsequently diagnosed with rarer cancers: a study of patient-reported data.
Br J Gen Pract. 2016 Mar;66(644):e171-81
Authors: Mendonca SC, Abel GA, Lyratzopoulos G
Abstract
BACKGROUND: Some patients with cancer experience multiple pre-diagnostic consultations in primary care, leading to longer time intervals to specialist investigations and diagnosis. Patients with rarer cancers are thought to be at higher risk of such events, but concrete evidence of this is lacking.
AIM: To examine the frequency and predictors of repeat consultations with GPs in patients with rarer cancers.
DESIGN AND SETTING: Patient-reported data on pre-referral consultations from three English national surveys of patients with cancer (2010, 2013, and 2014), pooled to maximise the sample size of rarer cancers.
METHOD: The authors examined the frequency and crude and adjusted odds ratios for ≥3 (versus 1-2) pre-referral consultations by age, sex, ethnicity, level of deprivation, and cancer diagnosis (38 diagnosis groups, including 12 rarer cancers without prior relevant evidence).
RESULTS: Among 7838 patients with 12 rarer cancers, crude proportions of patients with ≥3 pre-referral consultations ranged from >30.0% to 60.0% for patients with small intestine, bone sarcoma, liver, gallbladder, cancer of unknown primary, soft-tissue sarcoma, and ureteric cancer. The range was 15.0-30.0% for patients with oropharyngeal, anal, parotid, penile, and oral cancer. The overall proportion of responders with any cancer who had ≥3 consultations was 23.4%. Multivariable logistic regression indicated concordant patterns, with strong evidence for variation between rarer cancers (P <0.001).
CONCLUSION: Patients with rarer cancers experience pre-referral consultations at frequencies suggestive of middle-to-high diagnostic difficulty. The findings can guide the development of new diagnostic interventions and 'safety-netting' approaches for symptomatic presentations encountered in patients with rarer cancers.
PMID: 26917657 [PubMed - indexed for MEDLINE]
Large-scale data-driven integrative framework for extracting essential targets and processes from disease-associated gene data sets.
Large-scale data-driven integrative framework for extracting essential targets and processes from disease-associated gene data sets.
Brief Bioinform. 2017 May 18;:
Authors: Mazandu GK, Chimusa ER, Rutherford K, Zekeng EG, Gebremariam ZZ, Onifade MY, Mulder NJ
Abstract
Populations worldwide currently face several public health challenges, including growing prevalence of infections and the emergence of new pathogenic organisms. The cost and risk associated with drug development make the development of new drugs for several diseases, especially orphan or rare diseases, unappealing to the pharmaceutical industry. Proof of drug safety and efficacy is required before market approval, and rigorous testing makes the drug development process slow, expensive and frequently result in failure. This failure is often because of the use of irrelevant targets identified in the early steps of the drug discovery process, suggesting that target identification and validation are cornerstones for the success of drug discovery and development. Here, we present a large-scale data-driven integrative computational framework to extract essential targets and processes from an existing disease-associated data set and enhance target selection by leveraging drug-target-disease association at the systems level. We applied this framework to tuberculosis and Ebola virus diseases combining heterogeneous data from multiple sources, including protein-protein functional interaction, functional annotation and pharmaceutical data sets. Results obtained demonstrate the effectiveness of the pipeline, leading to the extraction of essential drug targets and to the rational use of existing approved drugs. This provides an opportunity to move toward optimal target-based strategies for screening available drugs and for drug discovery. There is potential for this model to bridge the gap in the production of orphan disease therapies, offering a systematic approach to predict new uses for existing drugs, thereby harnessing their full therapeutic potential.
PMID: 28520909 [PubMed - as supplied by publisher]
Social/economic costs and health-related quality of life in patients with rare diseases in Europe.
Social/economic costs and health-related quality of life in patients with rare diseases in Europe.
Eur J Health Econ. 2016 Apr;17 Suppl 1:1-5
Authors: López-Bastida J, Oliva-Moreno J, Linertová R, Serrano-Aguilar P
PMID: 27023708 [PubMed - indexed for MEDLINE]
Uveal melanoma: From diagnosis to treatment and the science in between.
Uveal melanoma: From diagnosis to treatment and the science in between.
Cancer. 2016 Aug 01;122(15):2299-312
Authors: Chattopadhyay C, Kim DW, Gombos DS, Oba J, Qin Y, Williams MD, Esmaeli B, Grimm EA, Wargo JA, Woodman SE, Patel SP
Abstract
Melanomas of the choroid, ciliary body, and iris of the eye are collectively known as uveal melanomas. These cancers represent 5% of all melanoma diagnoses in the United States, and their age-adjusted risk is 5 per 1 million population. These less frequent melanomas are dissimilar to their more common cutaneous melanoma relative, with differing risk factors, primary treatment, anatomic spread, molecular changes, and responses to systemic therapy. Once uveal melanoma becomes metastatic, therapy options are limited and are often extrapolated from cutaneous melanoma therapies despite the routine exclusion of patients with uveal melanoma from clinical trials. Clinical trials directed at uveal melanoma have been completed or are in progress, and data from these well designed investigations will help guide future directions in this orphan disease. Cancer 2016;122:2299-2312. © 2016 American Cancer Society.
PMID: 26991400 [PubMed - indexed for MEDLINE]
"Rare Diseases"[Mesh] OR "orphan disease"; +7 new citations
7 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:
"Rare Diseases"[Mesh] OR "orphan disease"
These pubmed results were generated on 2017/05/18
PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
"Rare Diseases"[Mesh] OR "orphan disease"; +7 new citations
7 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:
"Rare Diseases"[Mesh] OR "orphan disease"
These pubmed results were generated on 2017/05/18
PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Fibrodysplasia ossificans progressiva. A case report and focus on the BMP signaling pathway.
Fibrodysplasia ossificans progressiva. A case report and focus on the BMP signaling pathway.
Morphologie. 2016 Dec;100(331):250-255
Authors: Bouvard B, Masson C, Legrand E, Audran M
Abstract
Fibrodysplasia ossificans progressiva is a very rare heritable disease characterized by a progressive heterotopic endochondal ossification, occurring in the first decade of life, and leading thereafter to a severe ankylosis of the spine, limbs and jaw, with a progressive and severe functional disability. To date the cause of the disease remains unknown and no medical treatment has been proved efficient. It has recently been shown that a recurrent mutation in activation domain of the activin-receptor IA (ACVR1), a BMP receptor, could lead to an abnormal signalling pathway of BMP-4 and contribute to the occurrence of the devastating lesions characteristic of the disease.
PMID: 26948676 [PubMed - indexed for MEDLINE]
Treatment of rare factor deficiencies in 2016.
Treatment of rare factor deficiencies in 2016.
Hematology Am Soc Hematol Educ Program. 2016 Dec 02;2016(1):663-669
Authors: Peyvandi F, Menegatti M
Abstract
Rare bleeding disorders (RBDs) are a heterogeneous group of coagulation disorders characterized by fibrinogen, prothrombin, factors V, VII, X, XI, or XIII (FV, FVII, FX, FXI, or FXIII, respectively), and the combined factor V + VIII and vitamin K-dependent proteins deficiencies, representing roughly 5% of all bleeding disorders. They are usually transmitted as autosomal, recessive disorders, and the prevalence of the severe forms could range from 1 case in 500 000 for FVII up to 1 in 2-3 million for FXIII in the general population. Patients affected with RBDs may present a wide range of clinical symptoms, varying from mucocutaneous bleeding, common to all types of RBDs to the most life-threatening symptoms such as central nervous system and gastrointestinal bleeding. Treatment of these disorders is mainly based on the replacement of the deficient factor, using specific plasma-derived or recombinant products. In countries where these facilities are not available, bleedings could be managed using cryoprecipitate, fresh frozen plasma (FFP), or virus-inactivated plasma. Minor bleedings could be managed using antifibrinolytic agents. Recently, 2 novel drugs, recombinant FXIIIA and a plasma-derived FX, have been added to the list of available specific hemostatic factors; only prothrombin and FV deficiencies still remain without a specific product. Novel no-replacement therapies, such as monoclonal antibody anti-tissue factor pathway inhibitor, RNA interference, and a bispecific antibody that is an FVIIIa mimetic, enhancing thrombin generation through different mechanisms, were developed for patients with hemophilia and may in the future be a good therapeutic option also in RBDs.
PMID: 27913544 [PubMed - indexed for MEDLINE]
A novel 33-Gene targeted resequencing panel provides accurate, clinical-grade diagnosis and improves patient management for rare inherited anaemias.
A novel 33-Gene targeted resequencing panel provides accurate, clinical-grade diagnosis and improves patient management for rare inherited anaemias.
Br J Haematol. 2016 Oct;175(2):318-330
Authors: Roy NB, Wilson EA, Henderson S, Wray K, Babbs C, Okoli S, Atoyebi W, Mixon A, Cahill MR, Carey P, Cullis J, Curtin J, Dreau H, Ferguson DJ, Gibson B, Hall G, Mason J, Morgan M, Proven M, Qureshi A, Sanchez Garcia J, Sirachainan N, Teo J, Tedgård U, Higgs D, Roberts D, Roberts I, Schuh A
Abstract
Accurate diagnosis of rare inherited anaemias is challenging, requiring a series of complex and expensive laboratory tests. Targeted next-generation-sequencing (NGS) has been used to investigate these disorders, but the selection of genes on individual panels has been narrow and the validation strategies used have fallen short of the standards required for clinical use. Clinical-grade validation of negative results requires the test to distinguish between lack of adequate sequencing reads at the locations of known mutations and a real absence of mutations. To achieve a clinically-reliable diagnostic test and minimize false-negative results we developed an open-source tool (CoverMi) to accurately determine base-coverage and the 'discoverability' of known mutations for every sample. We validated our 33-gene panel using Sanger sequencing and microarray. Our panel demonstrated 100% specificity and 99·7% sensitivity. We then analysed 57 clinical samples: molecular diagnoses were made in 22/57 (38·6%), corresponding to 32 mutations of which 16 were new. In all cases, accurate molecular diagnosis had a positive impact on clinical management. Using a validated NGS-based platform for routine molecular diagnosis of previously undiagnosed congenital anaemias is feasible in a clinical diagnostic setting, improves precise diagnosis and enhances management and counselling of the patient and their family.
PMID: 27432187 [PubMed - indexed for MEDLINE]
"Rare Diseases"[Mesh] OR "orphan disease"; +8 new citations
8 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:
"Rare Diseases"[Mesh] OR "orphan disease"
These pubmed results were generated on 2017/05/13
PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Deficient activity of alanyl-tRNA synthetase underlies an autosomal recessive syndrome of progressive microcephaly, hypomyelination, and epileptic encephalopathy.
Deficient activity of alanyl-tRNA synthetase underlies an autosomal recessive syndrome of progressive microcephaly, hypomyelination, and epileptic encephalopathy.
Hum Mutat. 2017 May 11;:
Authors: Nakayama T, Wu J, Galvin-Parton P, Weiss J, Andriola MR, Hill RS, Vaughan D, El-Quessny M, Barry BJ, Partlow JN, Barkovich AJ, Ling J, Mochida GH
Abstract
Aminoacyl-transfer RNA (tRNA) synthetases ligate amino acids to specific tRNAs and are essential for protein synthesis. Although alanyl-tRNA synthetase (AARS) is a synthetase implicated in a wide range of neurological disorders from Charcot-Marie-Tooth (CMT) disease to infantile epileptic encephalopathy, there have been limited data on their pathogenesis. Here we report loss-of-function mutations in AARS in two siblings with progressive microcephaly with hypomyelination, intractable epilepsy and spasticity. Whole exome sequencing identified that the affected individuals were compound heterozygous for mutations in AARS gene, c.2067dupC (p.Tyr690Leufs*3) and c.2738G>A (p.Gly913Asp). A lymphoblastoid cell line developed from one of the affected individuals showed a strong reduction in AARS abundance. The mutations decrease aminoacylation efficiency by 70-90%. The p.Tyr690Leufs*3 mutation also abolished editing activity required for hydrolyzing misacylated tRNAs, thereby increasing errors during aminoacylation. Our study has extended potential mechanisms underlying AARS-related disorders to include destabilization of the protein, aminoacylation dysfunction, and defective editing activity. This article is protected by copyright. All rights reserved.
PMID: 28493438 [PubMed - as supplied by publisher]