Dataset Information

Rare variant (p.Ser43Asn) of familial transthyretin amyloidosis associated with isolated cardiac phenotype: A case series with literature review.

ABSTRACT:

Background

p.Ser43Asn is a very rare transthyretin (TTR) mutation leading to familial amyloidosis of transthyretin type, ATTR amyloidosis. It was previously observed in four patients worldwide and is associated almost invariably with an isolated cardiac phenotype.

Methods and results

We report here on an Italian family with early-onset cardiomyopathy and aggressive disease course in the affected individuals leading untreated to cardiac death before 55 years of age. We describe the clinical phenotype and imaging findings of two affected siblings, who were treated with tafamidis at an early disease stage, and their affected mother, who died 9 years ago due to refractory heart failure. The review of the available literature highlights the fact that until recently ATTR amyloidosis may have been misdiagnosed as other types of hypertrophic cardiomyopathy.

Conclusion

A better characterization of the genotype-phenotype associations is crucial to achieve optimal outcomes and facilitate informed decisions when treating individuals with rare mutations.

SUBMITTER: Papathanasiou M

PROVIDER: S-EPMC8683619 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BACKGROUND:Transthyretin amyloidosis (ATTR) is a heterogeneous disorder with multiorgan involvement and a genetic or nongenetic basis. OBJECTIVES:The goal of this study was to describe ATTR in the United States by using data from the THAOS (Transthyretin Amyloidosis Outcomes Survey) registry. METHODS:Demographic, clinical, and genetic features of patients enrolled in the THAOS registry in the United States (n = 390) were compared with data from patients from other regions of the world (ROW) (n = 2,140). The focus was on the phenotypic expression and survival in the majority of U.S. subjects with valine-to-isoleucine substitution at position 122 (Val122Ile) (n = 91) and wild-type ATTR (n = 189). RESULTS:U.S. subjects are older (70 vs. 46 years), more often male (85.4% vs. 50.6%), and more often of African descent (25.4% vs. 0.5%) than the ROW. A significantly higher percentage of U.S. patients with ATTR amyloid seen at cardiology sites had wild-type disease than the ROW (50.5% vs. 26.2%). In the United States, 34 different mutations (n = 201) have been reported, with the most common being Val122Ile (n = 91; 45.3%) and Thr60Ala (n = 41; 20.4%). Overall, 91 (85%) of 107 patients with Val122Ile were from the United States, where Val122Ile subjects were younger and more often female and black than patients with wild-type disease, and had similar cardiac phenotype but a greater burden of neurologic symptoms (pain, numbness, tingling, and walking disability) and worse quality of life. Advancing age and lower mean arterial pressure, but not the presence of a transthyretin mutation, were independently associated with higher mortality from a multivariate analysis of survival. CONCLUSIONS:In the THAOS registry, ATTR in the United States is overwhelmingly a disorder of older adult male subjects with a cardiac-predominant phenotype. Val122Ile is the most common transthyretin mutation, and neurologic phenotypic expression differs between wild-type disease and Val122Ile, but survival from enrollment in THAOS does not. (Transthyretin-Associated Amyloidoses Outcome Survey [THAOS]; NCT00628745).

Project description:AimCardiac troponins and natriuretic peptides are established for risk stratification in light-chain amyloidosis. Data on cardiac biomarkers in transthyretin amyloidosis (ATTR) are lacking.Methods and resultsPatients (n = 1617) with any of the following cardiac biomarkers, BNP (n = 1079), NT-proBNP (n = 550), troponin T (n = 274), and troponin I (n = 108), available at baseline in the Transthyretin Amyloidosis Outcomes Survey (THAOS) were analyzed for differences between genotypes and phenotypes and their association with survival. Median level of BNP was 68.0 pg/mL (IQR 30.5-194.9), NT-proBNP 337.9 pg/mL (IQR 73.0-2584.0), troponin T 0.03 μg/L (IQR 0.01-0.05), and troponin I 0.08 μg/L (IQR 0.04-0.13). NT-proBNP and BNP were higher in wild-type than mutant-type ATTR, troponin T and I did not differ, respectively. Non-Val30Met patients had higher BNP, NT-proBNP and troponin T levels than Val30Met patients, but not troponin I. Late-onset Val30Met was associated with higher levels of troponin I and troponin T compared with early-onset. 115 patients died during a median follow-up of 1.2 years. Mortality increased with increasing quartiles (BNP/NT-proBNP Q1 = 1.7%, Q2 = 5.2%, Q3 = 21.7%, Q4 = 71.3%; troponin T/I Q1 = 6.5%, Q2 = 14.5%, Q3 = 33.9%, Q4 = 45.2%). Three-year overall-survival estimates for BNP/NT-proBNP and troponin T/I quartiles differed significantly (p<0.001). Stepwise risk stratification was achieved by combining NT-proBNP/BNP and troponin T/I. From Cox proportional hazards model, age, modified body mass index, mutation (Val30Met vs. Non-Val30Met) and BNP/NT-proBNP (Q1-Q3 pooled vs. Q4) were identified as independent predictors of survival in patients with mutant-type ATTR.ConclusionsIn this ATTR patient cohort, cardiac biomarkers were abnormal in a substantial percentage of patients irrespective of genotype. Along with age, mBMI, and mutation (Val30Met vs. Non-Val30Met), cardiac biomarkers were associated with surrogates of disease severity with BNP/NT-proBNP identified as an independent predictor of survival in ATTR.Trial registrationClinicalTrials.gov NCT00628745.

Project description:Background The emergence of specific therapies for transthyretin cardiac amyloidosis (CA) warrants the need for a systematic review of the literature. Methods and Results A systematic review of the literature was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was performed on MEDLINE, PubMed, and Embase databases on November 29, 2019. Studies were selected based on the following predefined eligibility criteria: English-language randomized controlled trials (RCTs), non-RCTs, or observational studies, which included adult patients with variant/wild-type transthyretin-CA, assessed specific therapies for transthyretin-CA, and reported cardiovascular outcomes. Relevant data were extracted to a predefined template. Quality assessment was based on National Institute for Health and Care Excellence recommendations (RCTs) or a checklist by Downs and Black (non-RCTs). From 1203 records, 24 publications were selected, describing 4 RCTs (6 publications) and 16 non-RCTs (18 publications). Tafamidis was shown to significantly improve all-cause mortality and cardiovascular hospitalizations and reduce worsening in 6-minute walk test, Kansas City Cardiomyopathy Questionnaire-Overall Summary score, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) in variant/wild-type transthyretin-CA. Patisiran showed promising results in a subgroup analysis of patients with variant transthyretin-CA, which have to be confirmed in RCTs. Inotersen showed conflicting results on cardiac imaging parameters. The one study on AG10 had only a 1-month duration and cardiovascular end points were exploratory and limited to cardiac biomarkers. Limited evidence from noncomparative single-arm small non-RCTs existed for diflunisal, epigallocatechin-3-gallate (green tea extract), and doxycycline+tauroursodeoxycholic acid/ursodeoxycholic acid. Conclusions This systematic review of the literature supports the use of tafamidis in wild-type and variant transthyretin-CA. Novel therapeutic targets including transthyretin gene silencers are currently under investigation.

Project description:AimsCardiac transthyretin amyloidosis (ATTR-CM) is a progressive and fatal condition. Prognosis can be determined at diagnosis according to the National Amyloidosis Centre (NAC) transthyretin amyloidosis (ATTR) stage. We sought to examine how NAC ATTR stage changes during follow-up and whether it maintains its prognostic value throughout the disease course.Methods and resultsWe performed a retrospective study of 945 patients with wild-type ATTR-CM (wtATTR-CM) or hereditary ATTR-CM associated with the V122I variant (V122I-hATTR-CM) who were diagnosed and serially evaluated at the UK NAC. Patients who commenced any disease-modifying therapy for amyloidosis were censored at the time of doing so. Landmark Kaplan-Meier survival analyses were performed at diagnosis (n = 945) and at 6 ± 1 (n = 432), 12 ± 3 (n = 562), and 24 ± 3 (n = 316) months and stratified by recalculated NAC ATTR stage at the relevant time point. Cox regression analyses were performed to assess the prognostic significance during follow-up of an increase in NAC ATTR stage from Stage I at diagnosis. Mortality in ATTR-CM was predicted by NAC ATTR stage at each time point [Stage II vs. I, hazard ratios (HRs) 1.95-2.67; P < 0.001; Stage III vs. II, HRs 1.64-2.25; P < 0.001-0.013]. An increase from NAC ATTR Stage I, which occurred in 21%, 32%, and 44% of evaluable patients at 6, 12, and 24 months of follow-up respectively, was highly predictive of ongoing mortality at each time point (HRs 2.58-3.22; P < 0.001) and in each genotypic subgroup (HRs 1.86-4.38; P < 0.05). Increase in NAC ATTR stage occurred earlier in V122I-hATTR-CM than in wtATTR-CM (43% vs. 27% at 12 months of follow-up; P = 0.003).ConclusionsNational Amyloidosis Centre ATTR stage predicts ongoing survival throughout the disease natural history in ATTR-CM, and an increase from NAC ATTR Stage I at diagnosis to a higher NAC ATTR stage predicts mortality throughout follow-up. Serial calculation of NAC ATTR stage suggests a more aggressive phenotype in V122I-hATTR-CM than in wtATTR-CM.