rs1553242326

Positions:

• chr1-77942749-GGA-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_144573.4(NEXN):​c.1952_1953delAG​(p.Glu651fs) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,528 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NEXN NM_144573.4 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 10.0

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0375 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NEXN	NM_144573.4	c.1952_1953delAG	p.Glu651fs	frameshift_variant	13/13	ENST00000334785.12	NP_653174.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NEXN	ENST00000334785.12	c.1952_1953delAG	p.Glu651fs	frameshift_variant	13/13	1	NM_144573.4	ENSP00000333938.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461528 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727060

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 17, 2017

The c.1952_1953delAG variant, located in coding exon 12 of the NEXN gene, results from a deletion of two nucleotides at nucleotide positions 1952 to 1953, causing a translational frameshift with a predicted alternate stop codon (p.E651Vfs*4). This alteration is expected to result in loss of function by premature protein truncation, with loss of the C-terminal 24 amino acids. However, the mechanism of disease for NEXN mutations has not been clearly established, and the impact of this truncation on protein function is unclear. 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: rs1553242326; hg19: chr1-78408434;