Submissions for variant NM_000335.5(SCN5A):c.4339A>C (p.Ile1447Leu)

gnomAD frequency: 0.00003  dbSNP: rs199473250

Total submissions: 9

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	RCV000151779	SCV000200229	uncertain significance	not specified	2014-11-13	criteria provided, single submitter	clinical testing	Variant classified as Uncertain Significance - Favor Benign. The p.Ile1448Leu va riant in SCN5A has been reported in 1 individual with Brugada syndrome (Kappling er 2010) and was absent from large population studies. Isoleucine (Ile) at posit ion 1448 is not conserved in mammals or evolutionarily distant species and oposs um, Tasmanian devil, wallaby, and multiple birds and fish species carry a leucin e (Leu) at this position, suggesting that this change may be tolerated. Addition al computational prediction tools suggest that this variant may not impact the p rotein, though this information is not predictive enough to rule out pathogenici ty. In summary, while the clinical significance of the p.Ile1448Leu variant is u ncertain, the presence of the variant amino acid in multiple other species, incl uding mammals, suggests that it is more likely to be benign.
Ambry Genetics	RCV000252530	SCV000320056	uncertain significance	Cardiovascular phenotype	2022-03-09	criteria provided, single submitter	clinical testing	The c.4342A>C (p.I1448L) alteration is located in exon 25 (coding exon 24) of the SCN5A gene. This alteration results from a A to C substitution at nucleotide position 4342, causing the isoleucine (I) at amino acid position 1448 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.
Labcorp Genetics (formerly Invitae), Labcorp	RCV003488370	SCV000819309	uncertain significance	not provided	2024-12-28	criteria provided, single submitter	clinical testing	This sequence change replaces isoleucine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 1448 of the SCN5A protein (p.Ile1448Leu). This variant is present in population databases (rs199473250, gnomAD 0.005%). This missense change has been observed in individual(s) with SCN5A-related conditions (PMID: 20129283, 25351510, 34935411). ClinVar contains an entry for this variant (Variation ID: 67882). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The leucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.
Color Diagnostics, LLC DBA Color Health	RCV001842361	SCV001355727	uncertain significance	Cardiac arrhythmia	2023-03-28	criteria provided, single submitter	clinical testing	This missense variant replaces isoleucine with leucine at codon 1448 of the SCN5A protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with Brugada syndrome, hypertrophic cardiomyopathy, long QT syndrome, and dilated cardiomyopathy (PMID: 20129283, 25904541, 25351510, 27566755, 34935411). This variant has been identified in 9/248530 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.
Fulgent Genetics, Fulgent Genetics	RCV002490659	SCV002775067	uncertain significance	Brugada syndrome 1; Long QT syndrome 3; Sick sinus syndrome 1; Progressive familial heart block, type 1A; Ventricular fibrillation, paroxysmal familial, type 1; Dilated cardiomyopathy 1E; SUDDEN INFANT DEATH SYNDROME; Atrial fibrillation, familial, 10	2022-04-06	criteria provided, single submitter	clinical testing
Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein	RCV003137599	SCV003806975	uncertain significance	Long QT syndrome 3	2022-07-04	criteria provided, single submitter	clinical testing	ACMG classification criteria: PS4 supporting, PM2 moderated
Revvity Omics, Revvity	RCV003488370	SCV004237177	uncertain significance	not provided	2023-08-17	criteria provided, single submitter	clinical testing
All of Us Research Program, National Institutes of Health	RCV001842361	SCV004817133	uncertain significance	Cardiac arrhythmia	2024-07-20	criteria provided, single submitter	clinical testing	This missense variant replaces isoleucine with leucine at codon 1448 of the SCN5A protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with Brugada syndrome, hypertrophic cardiomyopathy, long QT syndrome, and dilated cardiomyopathy (PMID: 20129283, 25904541, 25351510, 27566755, 34935411). This variant has been identified in 9/248530 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.
Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust	RCV000058662	SCV000090182	not provided	Brugada syndrome		no assertion provided	literature only	This variant has been reported as associated with Brugada syndrome in the following publications (PMID:20129283). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory.