BabyScreen+ newborn screening
Gene: TRDN Amber List (moderate evidence)I don't know
Rated as 'strong actionability' for paediatric patients by ClinGen.
The mean age of onset of symptoms (usually a syncopal episode) of CPVT is between age seven and twelve years; onset as late as the fourth decade of life has been reported. Nearly 60% of patients have at least one syncopal episode before age 40. If untreated, CPVT is highly lethal, as approximately 30% of genetically affected individuals experience at least one cardiac arrest and up to 80% one or more syncopal spells. In untreated patients, the 8-year fatal or near-fatal event rates of 25% have been reported. Sudden death may be the first manifestation of the disease.
Beta-blockers lacking intrinsic sympathomimetic activity are recommended as a first-line therapy in all patients with a clinical diagnosis of CPVT, including those with documented spontaneous, stress-induced VAs. Guidelines differ in their recommendations about utilizing beta-blocker therapy in phenotype negative individuals. Treatment with beta blockers is associated with a reduction in adverse cardiac events. However, variability in outcome with beta-blocker therapy is due to multiple factors, including dosing and compliance. In a study of 101 patients with CPVT (22 diagnosed clinically and 79 diagnosed molecularly), 81 were administered beta-blockers (57 symptomatic and 24 asymptomatic individuals). Estimated 4- and 8-year cardiac event rates were 8% and 27%, respectively in patients taking beta-blockers, and 33% and 58% in those not taking beta blockers (log-rank p=0.01). Corresponding statistics for fatal events were 1% and 11% with beta-blockers vs. 18% and 25% without (log-rank p=0.05). Event rates in asymptomatic patients with a positive genotype were similar to other patients. In multivariate models, absence of beta-blockers was an independent predictor of cardiac events (hazard ratio [HR], 5.48; 95% CI, 1.8 to 16.7, p=0.003) and of fatal events (HR, 5.54; 95% CI, 1.2 to 26.1, p=0.03). Of the 37 asymptomatic patients with a positive genotype, 9 (24%) had cardiac events.
In patients with CPVT and recurrent sustained VT or syncope, while receiving adequate or maximally tolerated beta blocker, treatment intensification with either combination medication therapy (e.g., beta blocker with flecainide), left cardiac sympathetic denervation, and/or an ICD is recommended.
Clinical penetrance ranges from 25 to 100%, with an average of 70 to 80%. Syncope appears to be the first symptom in more than half of the patients. When untreated, mortality from CPVT is high, reaching 30 to 50% by the age of 30 years.
Reviewed with paediatric cardiologist: variable penetrance and age of onset, does not fulfil criteria for gNBS.Created: 29 Dec 2022, 8:41 a.m. | Last Modified: 29 Mar 2023, 1:42 a.m.
Panel Version: 0.2134
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Cardiac arrhythmia syndrome, with or without skeletal muscle weakness, MIM# 615441
Added phenotypes Cardiac arrhythmia syndrome, with or without skeletal muscle weakness, MIM# 615441 for gene: TRDN
Gene: trdn has been classified as Amber List (Moderate Evidence).
Tag for review was removed from gene: TRDN.
Gene: trdn has been classified as Green List (High Evidence).
Phenotypes for gene: TRDN were changed from Catecholaminergic polymorphic ventricular tachycardia to Cardiac arrhythmia syndrome, with or without skeletal muscle weakness, MIM# 615441
Gene: trdn has been classified as Green List (High Evidence).
Tag for review tag was added to gene: TRDN. Tag cardiac tag was added to gene: TRDN. Tag treatable tag was added to gene: TRDN.
gene: TRDN was added gene: TRDN was added to gNBS. Sources: Expert Review Red,BabySeq Category C gene Mode of inheritance for gene: TRDN was set to BIALLELIC, autosomal or pseudoautosomal Phenotypes for gene: TRDN were set to Catecholaminergic polymorphic ventricular tachycardia
If promoting or demoting a gene, please provide comments to justify a decision to move it.
Genes included in a Genomics England gene panel for a rare disease category (green list) should fit the criteria A-E outlined below.
These guidelines were developed as a combination of the ClinGen DEFINITIVE evidence for a causal role of the gene in the disease(a), and the Developmental Disorder Genotype-Phenotype (DDG2P) CONFIRMED DD Gene evidence level(b) (please see the original references provided below for full details). These help provide a guideline for expert reviewers when assessing whether a gene should be on the green or the red list of a panel.
A. There are plausible disease-causing mutations(i) within, affecting or encompassing an interpretable functional region(ii) of this gene identified in multiple (>3) unrelated cases/families with the phenotype(iii).
OR
B. There are plausible disease-causing mutations(i) within, affecting or encompassing cis-regulatory elements convincingly affecting the expression of a single gene identified in multiple (>3) unrelated cases/families with the phenotype(iii).
OR
C. As definitions A or B but in 2 or 3 unrelated cases/families with the phenotype, with the addition of convincing bioinformatic or functional evidence of causation e.g. known inborn error of metabolism with mutation in orthologous gene which is known to have the relevant deficient enzymatic activity in other species; existence of an animal model which recapitulates the human phenotype.
AND
D. Evidence indicates that disease-causing mutations follow a Mendelian pattern of causation appropriate for reporting in a diagnostic setting(iv).
AND
E. No convincing evidence exists or has emerged that contradicts the role of the gene in the specified phenotype.
(i)Plausible disease-causing mutations: Recurrent de novo mutations convincingly affecting gene function. Rare, fully-penetrant mutations - relevant genotype never, or very rarely, seen in controls. (ii) Interpretable functional region: ORF in protein coding genes miRNA stem or loop. (iii) Phenotype: the rare disease category, as described in the eligibility statement. (iv) Intermediate penetrance genes should not be included.
It’s assumed that loss-of-function variants in this gene can cause the disease/phenotype unless an exception to this rule is known. We would like to collect information regarding exceptions. An example exception is the PCSK9 gene, where loss-of-function variants are not relevant for a hypercholesterolemia phenotype as they are associated with increased LDL-cholesterol uptake via LDLR (PMID: 25911073).
If a curated set of known-pathogenic variants is available for this gene-phenotype, please contact us at panelapp@genomicsengland.co.uk
We classify loss-of-function variants as those with the following Sequence Ontology (SO) terms:
Term descriptions can be found on the PanelApp homepage and Ensembl.
If you are submitting this evaluation on behalf of a clinical laboratory please indicate whether you report variants in this gene as part of your current diagnostic practice by checking the box
Standardised terms were used to represent the gene-disease mode of inheritance, and were mapped to commonly used terms from the different sources. Below each of the terms is described, along with the equivalent commonly-used terms.
A variant on one allele of this gene can cause the disease, and imprinting has not been implicated.
A variant on the paternally-inherited allele of this gene can cause the disease, if the alternate allele is imprinted (function muted).
A variant on the maternally-inherited allele of this gene can cause the disease, if the alternate allele is imprinted (function muted).
A variant on one allele of this gene can cause the disease. This is the default used for autosomal dominant mode of inheritance where no knowledge of the imprinting status of the gene required to cause the disease is known. Mapped to the following commonly used terms from different sources: autosomal dominant, dominant, AD, DOMINANT.
A variant on both alleles of this gene is required to cause the disease. Mapped to the following commonly used terms from different sources: autosomal recessive, recessive, AR, RECESSIVE.
The disease can be caused by a variant on one or both alleles of this gene. Mapped to the following commonly used terms from different sources: autosomal recessive or autosomal dominant, recessive or dominant, AR/AD, AD/AR, DOMINANT/RECESSIVE, RECESSIVE/DOMINANT.
A variant on one allele of this gene can cause the disease, however a variant on both alleles of this gene can result in a more severe form of the disease/phenotype.
A variant in this gene can cause the disease in males as they have one X-chromosome allele, whereas a variant on both X-chromosome alleles is required to cause the disease in females. Mapped to the following commonly used term from different sources: X-linked recessive.
A variant in this gene can cause the disease in males as they have one X-chromosome allele. A variant on one allele of this gene may also cause the disease in females, though the disease/phenotype may be less severe and may have a later-onset than is seen in males. X-linked inactivation and mosaicism in different tissues complicate whether a female presents with the disease, and can change over their lifetime. This term is the default setting used for X-linked genes, where it is not known definitately whether females require a variant on each allele of this gene in order to be affected. Mapped to the following commonly used terms from different sources: X-linked dominant, x-linked, X-LINKED, X-linked.
The gene is in the mitochondrial genome and variants within this can cause this disease, maternally inherited. Mapped to the following commonly used term from different sources: Mitochondrial.
Mapped to the following commonly used terms from different sources: Unknown, NA, information not provided.
For example, if the mode of inheritance is digenic, please indicate this in the comments and which other gene is involved.