NM_001458.5:c.3790G>T

Variant names:

• chr7-128845255-G-T
• rs201335143
• NM_001458.5:c.3790G>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001458.5(FLNC):​c.3790G>T​(p.Gly1264Cys) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1264S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FLNC NM_001458.5 missense, splice_region
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.99
• 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 Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen, Ambry Genetics, G2P
• myofibrillar myopathy 5

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, G2P
• hypertrophic cardiomyopathy 26

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
• distal myopathy with posterior leg and anterior hand involvement

  Inheritance: AD Classification: MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics
• familial isolated restrictive cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• heart conduction disease

  Inheritance: AD Classification: LIMITED Submitted by: Genomics England PanelApp

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FLNC	NM_001458.5	c.3790G>T	p.Gly1264Cys	missense_variant, splice_region_variant	Exon 21 of 48	ENST00000325888.13	NP_001449.3
FLNC	NM_001127487.2	c.3790G>T	p.Gly1264Cys	missense_variant, splice_region_variant	Exon 21 of 47		NP_001120959.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FLNC	ENST00000325888.13	c.3790G>T	p.Gly1264Cys	missense_variant, splice_region_variant	Exon 21 of 48	1	NM_001458.5	ENSP00000327145.8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Apr 05, 2021

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

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

Jun 12, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with FLNC-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with cysteine at codon 1264 of the FLNC protein (p.Gly1264Cys). The glycine residue is moderately conserved and there is a large physicochemical difference between glycine and cysteine. This variant also falls at the last nucleotide of exon 21, which is part of the consensus splice site for this exon. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.63
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	35
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.87	D;.
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Pathogenic	0.57	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.6	H;H
PhyloP100		10
PrimateAI	Uncertain	0.56	T
PROVEAN	Pathogenic	-6.2	D;D
REVEL	Pathogenic	0.80
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.0040	D;D
Polyphen		1.0	D;D
Vest4		0.69
MutPred		0.79		Loss of disorder (P = 0.0218);Loss of disorder (P = 0.0218);
MVP		0.86
MPC		1.0
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.77
gMVP		0.76
Mutation Taster		=30/70	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.49		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.49		Position offset: 39
DS_DL_spliceai		0.27		Position offset: 0

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

Other links and lift over

dbSNP: rs201335143; hg19: chr7-128485309;