NM_144573.4:c.818G>A

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4BS1_SupportingBS2

The NM_144573.4(NEXN):​c.818G>A​(p.Arg273His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,613,824 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 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. R273C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

NEXN
NM_144573.4 missense

Scores

4
8
7

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 9.36

Publications

0 publications found
Variant links:
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)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.37718275).
BS1
Variant frequency is greater than expected in population afr. GnomAdExome4 allele frequency = 0.0000109 (16/1461742) while in subpopulation AFR AF = 0.000179 (6/33478). AF 95% confidence interval is 0.0000771. There are 0 homozygotes in GnomAdExome4. There are 9 alleles in the male GnomAdExome4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High AC in GnomAd4 at 5 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NEXNNM_144573.4 linkc.818G>A p.Arg273His missense_variant Exon 8 of 13 ENST00000334785.12 NP_653174.3 Q0ZGT2-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NEXNENST00000334785.12 linkc.818G>A p.Arg273His missense_variant Exon 8 of 13 1 NM_144573.4 ENSP00000333938.7 Q0ZGT2-1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152082
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000321
AC:
8
AN:
248876
AF XY:
0.0000296
show subpopulations
Gnomad AFR exome
AF:
0.000195
Gnomad AMR exome
AF:
0.0000580
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000109
AC:
16
AN:
1461742
Hom.:
0
Cov.:
32
AF XY:
0.0000124
AC XY:
9
AN XY:
727178
show subpopulations
African (AFR)
AF:
0.000179
AC:
6
AN:
33478
American (AMR)
AF:
0.0000447
AC:
2
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39660
South Asian (SAS)
AF:
0.0000696
AC:
6
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53380
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111964
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000329
AC:
5
AN:
152082
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74294
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41426
American (AMR)
AF:
0.000131
AC:
2
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10574
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.455
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.0000453
ExAC
AF:
0.0000248
AC:
3

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Cardiomyopathy Uncertain:1
Nov 04, 2019
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Uncertain:1
Apr 20, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R273H variant (also known as c.818G>A), located in coding exon 7 of the NEXN gene, results from a G to A substitution at nucleotide position 818. The arginine at codon 273 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Dilated cardiomyopathy 1CC;C3151267:Hypertrophic cardiomyopathy 20 Uncertain:1
Oct 11, 2017
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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has been observed in an individual affected with hypertrophic cardiomyopathy (PMID: 28790153). However, in that individual a pathogenic allele was also identified in MYH7, which suggests that this c.818G>A variant was not the primary cause of disease. This variant is present in population databases (rs765385072, ExAC 0.01%). This sequence change replaces arginine with histidine at codon 273 of the NEXN protein (p.Arg273His). The arginine residue is highly conserved and there is a small physicochemical difference between arginine and histidine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.15
BayesDel_addAF
Benign
-0.058
T
BayesDel_noAF
Uncertain
-0.040
CADD
Pathogenic
30
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.28
T;.;T;T
Eigen
Uncertain
0.48
Eigen_PC
Uncertain
0.49
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D;D;D;D
M_CAP
Benign
0.067
D
MetaRNN
Benign
0.38
T;T;T;T
MetaSVM
Uncertain
-0.21
T
MutationAssessor
Pathogenic
3.3
.;.;M;.
PhyloP100
9.4
PrimateAI
Benign
0.44
T
PROVEAN
Uncertain
-2.6
D;N;N;D
REVEL
Uncertain
0.33
Sift
Uncertain
0.0010
D;D;D;D
Sift4G
Uncertain
0.0060
D;D;D;D
Polyphen
1.0
.;.;D;.
Vest4
0.59, 0.55
MutPred
0.27
.;.;Loss of MoRF binding (P = 0.0329);.;
MVP
0.85
MPC
0.35
ClinPred
0.70
D
GERP RS
5.6
Varity_R
0.10
gMVP
0.17
Mutation Taster
=56/44
polymorphism

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

Other links and lift over

dbSNP: rs765385072; hg19: chr1-78392531; API