7-128855315-G-T

Variant names:

• chr7-128855315-G-T
• rs1554401581
• NM_001458.5:c.7251+1G>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001458.5(FLNC):​c.7251+1G>T variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000689 in 1,451,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: FLNC NM_001458.5 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.86
• Publications: 0 publications found

Genes affected

FLNC (HGNC:3756): (filamin C) This gene encodes one of three related filamin genes, specifically gamma filamin. These filamin proteins crosslink actin filaments into orthogonal networks in cortical cytoplasm and participate in the anchoring of membrane proteins for the actin cytoskeleton. Three functional domains exist in filamin: an N-terminal filamentous actin-binding domain, a C-terminal self-association domain, and a membrane glycoprotein-binding domain. Mutations in this gene are a cause of cardiopathy. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2022]

FLNC-AS1 (HGNC:53474): (FLNC antisense RNA 1)

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-128855315-G-T is Pathogenic according to our data. Variant chr7-128855315-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 859630.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FLNC	NM_001458.5	c.7251+1G>T		splice_donor_variant, intron_variant	Intron 43 of 47	ENST00000325888.13	NP_001449.3
FLNC	NM_001127487.2	c.7152+1G>T		splice_donor_variant, intron_variant	Intron 42 of 46		NP_001120959.1
FLNC-AS1	NR_149055.1	n.103-1918C>A		intron_variant	Intron 1 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FLNC	ENST00000325888.13	c.7251+1G>T		splice_donor_variant, intron_variant	Intron 43 of 47	1	NM_001458.5	ENSP00000327145.8

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.89e-7 AC: 1 AN: 1451048 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 722674

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33090

American (AMR) AF: 0.00 AC: 0 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26072

East Asian (EAS) AF: 0.00 AC: 0 AN: 39634

South Asian (SAS) AF: 0.00 AC: 0 AN: 86024

European-Finnish (FIN) AF: 0.0000189 AC: 1 AN: 52844

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1102900

Other (OTH) AF: 0.00 AC: 0 AN: 60018

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Myofibrillar myopathy 5;C3279722:Distal myopathy with posterior leg and anterior hand involvement;C4310749:Hypertrophic cardiomyopathy 26;CN239310:Dilated Cardiomyopathy, Dominant Pathogenic:1

Mar 09, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This sequence change affects a donor splice site in intron 43 of the FLNC gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). Disruption of this splice site has been observed in individual(s) with dilated cardiomyopathy (PMID: 27908349, 28008423). Experimental studies have shown that a different nucleotide change at this splice site disrupts mRNA splicing (PMID: 28008423). Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in FLNC are known to be pathogenic (PMID: 27908349).

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.25
CADD	Pathogenic	36
DANN	Uncertain	1.0
DEOGEN2	Benign	0.0	.;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.0	.;.
MetaRNN	Benign	0.0	.;.
MutationAssessor	Benign	0.0	.;.
PhyloP100		9.9
PROVEAN	Benign	0.0	.;.
REVEL	Benign	0.0
Sift	Pathogenic	0.0	.;.
Sift4G	Pathogenic	0.0	.;.
Vest4		0.0
GERP RS		5.3
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.50		Position offset: 12
DS_DL_spliceai		1.0		Position offset: -1

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

Other links and lift over

dbSNP: rs1554401581; hg19: chr7-128495369;