NM_144573.4:c.1348dupA

Variant names:

• chr1-77935914-T-TA
• rs1553240600
• NM_144573.4:c.1348dupA

Variant summary

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

The NM_144573.4(NEXN):​c.1348dupA​(p.Ser450LysfsTer4) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: NEXN NM_144573.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.175
• Publications: 0 publications found

Genes affected

NEXN (HGNC:29557): (nexilin F-actin binding protein) This gene encodes a filamentous actin-binding protein that may function in cell adhesion and migration. Mutations in this gene have been associated with dilated cardiomyopathy, also known as CMD1CC. Alternatively spliced transcript variants have been described.[provided by RefSeq, Feb 2010]

NEXN Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy 1CC

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• hypertrophic cardiomyopathy 20

  Inheritance: AD Classification: LIMITED Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae)

ACMG classification

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

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-77935914-T-TA is Pathogenic according to our data. Variant chr1-77935914-T-TA is described in ClinVar as Pathogenic. ClinVar VariationId is 538107.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NEXN	NM_144573.4	c.1348dupA	p.Ser450LysfsTer4	frameshift_variant	Exon 11 of 13	ENST00000334785.12	NP_653174.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NEXN	ENST00000334785.12	c.1348dupA	p.Ser450LysfsTer4	frameshift_variant	Exon 11 of 13	1	NM_144573.4	ENSP00000333938.7

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dilated cardiomyopathy 1CC;C3151267:Hypertrophic cardiomyopathy 20 Pathogenic:1

May 26, 2023

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. ClinVar contains an entry for this variant (Variation ID: 538107). This variant has not been reported in the literature in individuals affected with NEXN-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Ser450Lysfs*4) in the NEXN gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in NEXN are known to be pathogenic (PMID: 32058062, 32814711, 32870709, 33949776). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.17

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

Other links and lift over

dbSNP: rs1553240600; hg19: chr1-78401599;