chr19-49200317-AC-A

Variant names:

• chr19-49200317-AC-A
• rs777047595
• NM_017636.4:c.2665delC

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_017636.4(TRPM4):​c.2665delC​(p.His889ThrfsTer35) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000164 in 1,613,962 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.00012 (0 hom., cov: 31)
  • Exomes 𝑓: 0.00017 (0 hom.)
• Consequence: TRPM4 NM_017636.4 frameshift
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:7
• Conservation: PhyloP100: 0.0990

Genes affected

TRPM4 (HGNC:17993): (transient receptor potential cation channel subfamily M member 4) The protein encoded by this gene is a calcium-activated nonselective ion channel that mediates transport of monovalent cations across membranes, thereby depolarizing the membrane. The activity of the encoded protein increases with increasing intracellular calcium concentration, but this channel does not transport calcium. [provided by RefSeq, Mar 2016]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• BS2: High AC in GnomAd4 at 19 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TRPM4	NM_017636.4	c.2665delC	p.His889ThrfsTer35	frameshift_variant	Exon 18 of 25	ENST00000252826.10	NP_060106.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TRPM4	ENST00000252826.10	c.2665delC	p.His889ThrfsTer35	frameshift_variant	Exon 18 of 25	1	NM_017636.4	ENSP00000252826.4

Frequencies

GnomAD3 genomes AF: 0.000125 AC: 19 AN: 151962 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000656

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000235

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000135 AC: 34 AN: 251264 Hom.: 0 AF XY: 0.000155 AC XY: 21 AN XY: 135816

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000264

Gnomad OTH exome AF: 0.000326

GnomAD4 exome AF: 0.000168 AC: 246 AN: 1461882 Hom.: 0 Cov.: 32 AF XY: 0.000149 AC XY: 108 AN XY: 727244

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000206

Gnomad4 OTH exome AF: 0.000116

GnomAD4 genome AF: 0.000125 AC: 19 AN: 152080 Hom.: 0 Cov.: 31 AF XY: 0.0000673 AC XY: 5 AN XY: 74342

Gnomad4 AFR AF: 0.0000482

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000235

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000260 Hom.: 0

Bravo AF: 0.0000982

EpiCase AF: 0.000327

EpiControl AF: 0.000356

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Feb 25, 2020	Has not been previously published as pathogenic or benign to our knowledge; Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is not a known mechanism of disease; Reported in ClinVar as a variant of uncertain significance (ClinVar Variant ID# 422801; Landrum et al., 2016); This variant is associated with the following publications: (PMID: 30847666) -
Uncertain significance, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -

Progressive familial heart block type IB Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Sep 01, 2017	The TRPM4 c.2665delC (p.His889ThrfsTer35) variant results in a frameshift, and is predicted to result in premature termination of the protein. A literature search was performed for the gene, cDNA change, and amino acid change. No publications were found based on this search. Based on the variant frequency, disease prevalence, disease penetrance, and inheritance mode, this variant could not be ruled out of causing disease. Due to the potential impact of frameshift variants and the lack of clarifying evidence, this variant is classified as a variant of unknown significance but suspicious for pathogenicity for progressive familial heart block. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 20, 2024	This sequence change creates a premature translational stop signal (p.His889Thrfs*35) in the TRPM4 gene. It is expected to result in an absent or disrupted protein product. However, the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in TRPM4 cause disease. This variant is present in population databases (rs777047595, gnomAD 0.03%). This premature translational stop signal has been observed in individual(s) with catecholaminergic polymorphic ventricular tachycardia (PMID: 30847666). ClinVar contains an entry for this variant (Variation ID: 422801). 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. -

Progressive familial heart block type IB;C5193144:Erythrokeratodermia variabilis et progressiva 6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 20, 2021

- -

Long QT syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

research

Dept of Medical Biology, Uskudar University

Jan 08, 2024

Criteria: PVS1_Moderate -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 12, 2024

The c.2665delC variant, located in coding exon 18 of the TRPM4 gene, results from a deletion of one nucleotide at nucleotide position 2665, causing a translational frameshift with a predicted alternate stop codon (p.H889Tfs*35). This variant was detected in an arrhythmia genetic testing cohort; however, clinical details were limited (van Lint FHM et al. Neth Heart J, 2019 Jun;27:304-309).This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. However, loss of function of TRPM4 has not been clearly established as a mechanism of disease. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs777047595; hg19: chr19-49703574;