1
|
Adams D, Sekijima Y, Conceição I, Waddington-Cruz M, Polydefkis M, Echaniz-Laguna A, Reilly MM. Hereditary transthyretin amyloid neuropathies: advances in pathophysiology, biomarkers, and treatment. Lancet Neurol 2023; 22:1061-1074. [PMID: 37863593 DOI: 10.1016/s1474-4422(23)00334-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 08/08/2023] [Accepted: 08/31/2023] [Indexed: 10/22/2023]
Abstract
Hereditary transthyretin (TTR) amyloid polyneuropathy is an autosomal dominant life-threatening disorder. TTR is produced mainly by the liver but also by the choroid plexus and retinal pigment epithelium. Detailed clinical characterisation, identification of clinical red flags for misdiagnosis, and use of biomarkers enable early diagnosis and treatment. In addition to liver transplantation and TTR stabilisers, three other disease-modifying therapies have regulatory approval: one antisense oligonucleotide (inotersen) and two small interfering RNAs (siRNAs; patisiran and vutrisiran). The siRNAs have been shown to stop progression of neuropathy and improve patients' quality of life. As none of the disease-modifying therapies can cross the blood-brain barrier, TTR deposition in the CNS, which can cause stroke and cognitive impairment, remains an important unaddressed issue. CRISPR-Cas9-based one-time TTR editing therapy is being investigated in a phase 1 clinical study. Identification of the earliest stages of pathogenesis in TTR variant carriers is a major challenge that needs addressing for optimal management.
Collapse
Affiliation(s)
- David Adams
- Department of Neurology, Bicêtre Centre Hospitalo Universitaire, AP-HP, INSERM U 1195, University Paris Saclay, Le Kremlin Bicetre, France.
| | - Yoshiki Sekijima
- Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto, Japan
| | - Isabel Conceição
- Department of Neurosciences and Mental Health, Centro Hospitalar Universitario Lisboas Norte-Hospital de Santa Maria and Centro de Estudos Egas Moniz, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
| | - Marcia Waddington-Cruz
- Centro de Estudos em Paramiloidose Antonio Rodrigues de Mello, National Amyloidosis Referral Center, University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Michael Polydefkis
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Andoni Echaniz-Laguna
- Department of Neurology, Centre Hospitalo Universitaire, AP-HP, INSERM U 1195, University Paris Saclay, Le Kremlin Bicetre Cedex, France
| | - Mary M Reilly
- Department of Neuromuscular Disease, University College London Institute of Neurology and the National Hospital of Neurology and Neurosurgery, London, UK
| |
Collapse
|
2
|
Warendorf JK, van der Star GM, Dooijes D, Notermans NC, Vrancken AFJE. Red flags and adjusted suspicion index for distinguishing hereditary transthyretin amyloid polyneuropathy from idiopathic axonal polyneuropathy. Neurol Sci 2023; 44:3679-3685. [PMID: 37266816 PMCID: PMC10495272 DOI: 10.1007/s10072-023-06859-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 05/16/2023] [Indexed: 06/03/2023]
Abstract
BACKGROUND Early diagnosis of hereditary ATTR polyneuropathy (ATTRv-PN) is important since treatment options have become available, which are most effective early in the disease course. ATTRv-PN is likely underdiagnosed as patients might be misdiagnosed with idiopathic polyneuropathy. It is uncertain if it is useful to test for TTR gene mutations in patients with a typical presentation for chronic idiopathic axonal polyneuropathy (CIAP) and which are the distinguishing clinical features. METHODS We carried out a retrospective cohort study to assess the yield of TTR gene sequencing in patients with polyneuropathy and assessed if the identified patients with ATTRv-PN had a clinical presentation typical of CIAP. Additionally, we assessed which clinical features, including previously defined red flag symptoms, can differentiate between patients with CIAP and ATTRv-PN and assessed the performance of the TTR suspicion index. RESULTS Out of 338 patients with polyneuropathy, 10 patients had a pathogenic TTR gene mutation (all p.Val50Met) and none had a clinical presentation typical of CIAP. Patients with ATTRv-PN more often had bilateral CTS, motor involvement of arms, cardiac involvement, family history suggestive of hATTRv, and autonomic symptoms than patients with CIAP. All patients with ATTRv-PN as well as 70% of patients with CIAP fulfilled the suspicion index. CONCLUSION Routine TTR gene sequencing in patients with a typical presentation for CIAP is not useful. However, red flag symptoms can differentiate patients with ATTRv-PN from patients with CIAP. We propose an adjusted version of the TTR suspicion index to increase diagnostic yield.
Collapse
Affiliation(s)
- Janna K Warendorf
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, 3584 CX, Utrecht, The Netherlands.
| | - Gerjan M van der Star
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, 3584 CX, Utrecht, The Netherlands
| | - Dennis Dooijes
- Department of Genetics, University Medical Center Utrecht, 3584 CX, Utrecht, The Netherlands
| | - Nicolette C Notermans
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, 3584 CX, Utrecht, The Netherlands
| | - Alexander F J E Vrancken
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, 3584 CX, Utrecht, The Netherlands
| |
Collapse
|
3
|
Whitlock RH, Nour-Mohammadi M, Curtis S, Komenda P, Bohm C, Collister D, Tangri N, Rigatto C. Magnitude of the Potential Screening Gap for Fabry Disease in
Manitoba: A Population-Based Retrospective Cohort Study. Can J Kidney Health Dis 2023; 10:20543581231162218. [PMID: 36970566 PMCID: PMC10031591 DOI: 10.1177/20543581231162218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 01/28/2023] [Indexed: 03/24/2023] Open
Abstract
Background: Fabry disease is a rare disorder caused by the deficient activity of
α-galactosidase A (GLA) that often leads to organ damage. Fabry disease can
be treated with enzyme replacement or pharmacological therapy, but due to
its rarity and nonspecific manifestations, it often goes undiagnosed. Mass
screening for Fabry disease is impractical; however, a targeted screening
program for high-risk individuals may uncover previously unknown cases. Objective: Our objective was to use population-level administrative health databases to
identify patients at high risk of Fabry disease. Design: Retrospective cohort study. Setting: Population-level health administrative databases housed at the Manitoba
Centre for Health Policy. Patients: All residents of Manitoba, Canada, between 1998 and 2018. Measurements: We ascertained the evidence of GLA testing in a cohort of patients at high
risk of Fabry disease. Methods: Individuals without a hospitalization or prescription indicative of Fabry
disease were included if they had evidence of 1 of 4 high-risk conditions
for Fabry disease: (1) ischemic stroke <45 years of age, (2) idiopathic
hypertrophic cardiomyopathy, (3) proteinuric chronic kidney disease or
kidney failure of unknown cause, or (4) peripheral neuropathy. Patients were
excluded if they had known contributing factors to these high-risk
conditions. Those who remained and had no prior GLA testing were assigned a
0% to 4.2% probability of having Fabry disease depending on their high-risk
condition and sex. Results: After applying exclusion criteria, 1386 individuals were identified as having
at least 1 high-risk clinical condition for Fabry disease in Manitoba. There
were 416 GLA tests conducted during the study period, and of those, 22 were
conducted in individuals with at least 1 high-risk condition. This leaves a
screening gap of 1364 individuals with a high-risk clinical condition for
Fabry disease in Manitoba who have not been tested. At the end of the study
period, 932 of those individuals were still alive and residing in Manitoba,
and if screened today, we expect between 3 and 18 would test positive for
Fabry disease. Limitations: The algorithms we used to identify our patients have not been validated
elsewhere. Diagnoses of Fabry disease, idiopathic hypertrophic
cardiomyopathy, and peripheral neuropathy were only available via
hospitalizations and not physician claims. We were only able to capture GLA
testing processed through public laboratories. Patients identified to be at
high risk of Fabry disease by the algorithm did not undergo GLA testing due
to a clinical rationale that we were unable to capture. Conclusions: Administrative health databases may be a useful tool to identify patients at
higher risk of Fabry disease or other rare conditions. Further directions
include designing a program to screen high-risk individuals for Fabry
disease as identified by our administrative data algorithms.
Collapse
Affiliation(s)
- Reid H. Whitlock
- Chronic Disease Innovation Centre,
Seven Oaks General Hospital, Winnipeg, MB, Canada
- Reid H. Whitlock, Chronic Disease
Innovation Centre, Seven Oaks General Hospital, 2LB19-2300 McPhillips Street,
Winnipeg, MB R2V 3M3, Canada.
| | - Mohammad Nour-Mohammadi
- Chronic Disease Innovation Centre,
Seven Oaks General Hospital, Winnipeg, MB, Canada
- Department of Internal Medicine,
University of Manitoba, Winnipeg, Canada
| | - Sarah Curtis
- Chronic Disease Innovation Centre,
Seven Oaks General Hospital, Winnipeg, MB, Canada
| | - Paul Komenda
- Chronic Disease Innovation Centre,
Seven Oaks General Hospital, Winnipeg, MB, Canada
- Department of Internal Medicine,
University of Manitoba, Winnipeg, Canada
| | - Clara Bohm
- Chronic Disease Innovation Centre,
Seven Oaks General Hospital, Winnipeg, MB, Canada
- Department of Internal Medicine,
University of Manitoba, Winnipeg, Canada
| | - David Collister
- Chronic Disease Innovation Centre,
Seven Oaks General Hospital, Winnipeg, MB, Canada
- Department of Medicine, University of
Alberta, Edmonton, Canada
| | - Navdeep Tangri
- Chronic Disease Innovation Centre,
Seven Oaks General Hospital, Winnipeg, MB, Canada
- Department of Internal Medicine,
University of Manitoba, Winnipeg, Canada
| | - Claudio Rigatto
- Chronic Disease Innovation Centre,
Seven Oaks General Hospital, Winnipeg, MB, Canada
- Department of Internal Medicine,
University of Manitoba, Winnipeg, Canada
| |
Collapse
|
4
|
Samuelsson K, Jovanovic A, Egervall K, Anan I, Wixner J, Press R. Hereditary transthyretin amyloidosis in Sweden: Comparisons between a non-endemic and an endemic region. Amyloid 2022; 29:220-227. [PMID: 35438016 DOI: 10.1080/13506129.2022.2065191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Hereditary transthyretin amyloidosis (ATTRv) is endemic in northern Sweden (Västerbotten). The awareness of ATTRv amyloidosis is lower in Stockholm, a non-endemic region in Sweden. The aim of this study was to compare the possible differences in diagnostic delay, disease phenotypes, treatment and survival between a non-endemic and an endemic region in Sweden. METHODS The in- and outpatient diagnosis registry at the Department of Neurology at Karolinska University Hospital and the Amyloidosis Centre at University Hospital of Umeå were used to identify patients between January 2006 and November 2017. RESULTS In total, 21 patients in Stockholm and 134 patients in Västerbotten were included. The time between symptom onset to time-point of diagnosis was significantly longer in Stockholm vs Västerbotten. This corresponded to a longer median time between first visit at amyloidosis centre to time-point of diagnosis in Stockholm vs in Västerbotten. The most common reason for a diagnostic delay was negative tissue biopsies. CONCLUSION There was a diagnostic-, but no patient-delay in non-endemic Stockholm vs endemic Västerbotten. Despite a more severe neuropathic phenotype in Stockholm at the onset, the systemic affection over the course of disease and of survival seems not to be influenced by the diagnosis delay in Stockholm.
Collapse
Affiliation(s)
- Kristin Samuelsson
- Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Ana Jovanovic
- Department of Neurology, Karolinska University Hospital, Stockholm, Sweden
| | - Karl Egervall
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Intissar Anan
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.,Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Jonas Wixner
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Rayomand Press
- Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
5
|
Bitzi LM, Lehnick D, Wilder-Smith EP. Small fiber neuropathy: Swiss cohort characterization. Muscle Nerve 2021; 64:293-300. [PMID: 34075618 PMCID: PMC8453953 DOI: 10.1002/mus.27340] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 05/27/2021] [Accepted: 05/30/2021] [Indexed: 12/13/2022]
Abstract
Introduction/Aim There is currently insufficient clinical and epidemiological data concerning small fiber neuropathy (SFN). This research analyzes data from medical records to determine epidemiology, demographics, clinical characteristics and etiology of SFN. Methods This is a retrospective, observational study of sequential patients diagnosed with definite SFN (typical clinical features, normal nerve conduction studies, abnormal epidermal nerve fiber density) from the end of November 2016 to the middle of July 2019 at the Cantonal Hospital Lucerne, central Switzerland. Results A total of 84 patients (64.3% female) with a mean age of 54.7 y were analyzed. Symptoms had been present in patients for an average of 4.8 y when entering the study. A length dependent clinical pattern was seen in 79.8%. All patients had sensory discomfort. Etiology could not be determined in 35.7% of patients, who were diagnosed with idiopathic SFN; 34.5% of patients had an apparently autoimmune SFN, followed by14.3% of patients with metabolic causes. The estimated incidence was at least 4.4 cases/100.000 inhabitants/y. The minimum prevalence was 131.5 cases/100.000 inhabitants. Discussion This study indicates significant incidence and prevalence rates of SFN in Switzerland. SFN can vary greatly in its symptoms and severity. Extensive work‐up resulted in two thirds of the patients being assigned an etiological association. The largest group of patients could not be etiologically defined, underlining the importance of further research on etiologic identification. We expect increased awareness of the developing field of SFN.
Collapse
Affiliation(s)
- Lorena M Bitzi
- Faculty of Medicine, University of Bern, Bern, Switzerland
| | - Dirk Lehnick
- Department of Health Sciences and Medicine, University of Lucerne, Lucerne, Switzerland
| | - Einar P Wilder-Smith
- Faculty of Medicine and Cantonal Hospital Lucerne, Centre for Neurology, University of Bern, Bern, Switzerland
| |
Collapse
|
6
|
Abstract
PURPOSE OF REVIEW Chronic idiopathic axonal polyneuropathy (CIAP), a common neurological condition, is considered to be a benign neurological condition with a small risk of disability. However, many studies have shown a reduced quality of life and a nonnegligible affection of daily activities in patients with CIAP. Here we summarize recent data about CIAP. RECENT FINDINGS We discuss some of the latest articles regarding risk factors, comorbidities, and possible pathogenic factors regarding CIAP. Patients with chronic polyneuropathy have impaired walking capacity, disturbed balance, and an increased risk of falls. Idiopathic polyneuropathy has a negative impact on activities of daily living. Patients with CIAP may develop plantar ulcers and neuropathic arthropathy. Small fiber involvement may occur, and two recent studies indicate that neuropathic pain is present in about two thirds of the CIAP group. Furthermore, patients with CIAP with neuropathic pain have increased fatigue and poorer emotional well being. SUMMARY Despite the relatively mild motor impairment seen in most patients with CIAP, the condition causes limitations in life with decreased mobility, pain, and affection of basal daily activities. Because the pathogenesis of CIAP in unclear, there is no disease modifying treatment. Further studies regarding pathogenesis, and randomized controlled clinical trials regarding possible treatment options are needed.
Collapse
|
7
|
Burton A, Castaño A, Bruno M, Riley S, Schumacher J, Sultan MB, See Tai S, Judge DP, Patel JK, Kelly JW. Drug Discovery and Development in Rare Diseases: Taking a Closer Look at the Tafamidis Story. Drug Des Devel Ther 2021; 15:1225-1243. [PMID: 33776421 PMCID: PMC7987260 DOI: 10.2147/dddt.s289772] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 01/20/2021] [Indexed: 12/25/2022] Open
Abstract
Rare diseases are increasingly recognized as a global public health priority. Governments worldwide currently provide important incentives to stimulate the discovery and development of orphan drugs for the treatment of these conditions, but substantial scientific, clinical, and regulatory challenges remain. Tafamidis is a first-in-class, disease-modifying transthyretin (TTR) kinetic stabilizer that represents a major breakthrough in the treatment of transthyretin amyloidosis (ATTR amyloidosis). ATTR amyloidosis is a rare, progressive, and fatal systemic disorder caused by aggregation of misfolded TTR and extracellular deposition of amyloid fibrils in various tissues and organs, including the heart and nervous systems. In this review, we present the successful development of tafamidis spanning 3 decades, marked by meticulous laboratory research into disease mechanisms and natural history, and innovative clinical study design and implementation. These efforts established the safety and efficacy profile of tafamidis, leading to its regulatory approval, and enabled post-approval initiatives that further support patients with ATTR amyloidosis.
Collapse
Affiliation(s)
| | | | | | - Steve Riley
- Clinical Pharmacology, Pfizer Inc, Groton, CT, USA
| | | | - Marla B Sultan
- Global Product Development, Pfizer Inc, New York, NY, USA
| | - Sandi See Tai
- Global Product Development, Pfizer Inc, Collegeville, PA, USA
| | - Daniel P Judge
- Department of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Jignesh K Patel
- Department of Cardiology, Cedars-Sinai Smidt Heart Institute, Los Angeles, CA, USA
| | - Jeffery W Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| |
Collapse
|
8
|
Rota E, Grandis M, Di Sapio A, Ghiglione E, Fiorentino P, Repetto A, Giliberto C, Gemelli C, Morelli N, Schenone A, Cocito D. Screening for Fabry disease in unknown origin axonal polyneuropathy: to do or not to do, this is the question! Orphanet J Rare Dis 2020; 15:216. [PMID: 32819406 PMCID: PMC7439676 DOI: 10.1186/s13023-020-01501-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 08/07/2020] [Indexed: 11/17/2022] Open
Abstract
Fabry disease (FD) is a systemic X-linked lysosomal disorder. A ‘peripheral nerve variant’ of FD has been hypothesized in subjects with neuropathy, without the early manifestations of the classic phenotype. A cohort of undiagnosed neuropathy patients with chronic polyneuropathy of undetermined aetiology and demyelinating neuropathy, unresponsive to immunomodulating treatment, were screened for FD. A total of 103 patients (64% males), were enrolled. No typical pathogenetic mutations for FD were identified. We are aware that the study sample was very small, but only a large, unfeasible theoretical sample size could demonstrate a statistically significant increased prevalence of FD in neuropathy patients, as peripheral neuropathy of undetermined cause is uncommon and there is a low prevalence of FD in the general population. Therefore, we are of the opinion that including tailored FD screening in the neuropathy diagnostic work-up, particularly when there are additional clinical characteristics, should be considered.
Collapse
|
9
|
Haroutounian S, Todorovic MS, Leinders M, Campagnolo M, Gewandter JS, Dworkin RH, Freeman R. Diagnostic criteria for idiopathic small fiber neuropathy: A systematic review. Muscle Nerve 2020; 63:170-177. [PMID: 32989823 DOI: 10.1002/mus.27070] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 09/05/2020] [Accepted: 09/11/2020] [Indexed: 12/19/2022]
Abstract
Idiopathic small fiber neuropathy (iSFN) lacks broadly accepted diagnostic criteria, which hinders its timely diagnosis and treatment. A systematic literature review was performed to assess the published screening and diagnostic criteria for iSFN, excluding studies where SFN was of well-established etiology. Eighty-four clinical studies and seven guideline/review publications were included in this systematic review. Substantial heterogeneity existed in iSFN diagnostic criteria. The most common set of criteria to diagnose iSFN [presence of any symptoms of iSFN, absence of large fiber involvement, and reduced intraepidermal nerve fiber density (IENFD)] was used in only 14% of studies. Mandatory individual criteria to confirm iSFN included any sensory symptoms (60% of studies), pain (19% of studies), small fiber signs (20% of studies), absence of large fiber signs (62% of studies), reduced IENFD (38% of studies), and autonomic symptoms (1% of studies). This review highlights a clear need for standardized, evidence-based guidelines for diagnosing iSFN.
Collapse
Affiliation(s)
- Simon Haroutounian
- Washington University Pain Center and Division of Clinical and Translational Research, Department of Anesthesiology, Washington University in St Louis School of Medicine, St Louis, Missouri, USA
| | - Marko S Todorovic
- Washington University Pain Center and Division of Clinical and Translational Research, Department of Anesthesiology, Washington University in St Louis School of Medicine, St Louis, Missouri, USA
| | - Mathias Leinders
- Washington University Pain Center and Division of Clinical and Translational Research, Department of Anesthesiology, Washington University in St Louis School of Medicine, St Louis, Missouri, USA
| | - Marta Campagnolo
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Jennifer S Gewandter
- Department of Anesthesiology and Perioperative Medicine, University of Rochester School of Medicine, Rochester, New York, USA
| | - Robert H Dworkin
- Department of Anesthesiology and Perioperative Medicine, University of Rochester School of Medicine, Rochester, New York, USA
| | - Roy Freeman
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
10
|
Abstract
Background and objectives: Transthyretin familial amyloid polyneuropathy (TTR-FAP) is caused by a mutation in the transthyretin (TTR) gene. Although classically described as rapidly progressive and life-threatening, recent studies on TTR-FAP show significant genetic and phenotypic heterogeneity depending on geographic localization. In light of new therapeutic advances and their implication for patient management, the aim of our study was to determine the prevalence of TTR-FAP within patients with idiopathic neuropathy in a North American population. Methods: We sequenced the TTR gene in a cohort of patients with idiopathic neuropathy. Genetic screening was performed in 110 patients from two neuromuscular clinics in Montreal, Canada. Results: No variants of unknown significance or pathogenic mutations were detected in the TTR gene. Conclusion: Our study confirms that TTR-FAP is a rare entity in our patient population, and that diagnostic yield of screening all patients with idiopathic neuropathy is very low.
Collapse
|
11
|
Screening for genetic mutations in patients with neuropathy without definite etiology is useful. J Neurol 2020; 267:2648-2654. [DOI: 10.1007/s00415-020-09899-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 10/24/2022]
|