rs1318084676

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_198576.4(AGRN):​c.904G>A​(p.Ala302Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000131 in 1,529,004 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A302G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 7.3e-7 ( 0 hom. )

Consequence

AGRN
NM_198576.4 missense

Scores

13
5

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.24

Publications

0 publications found
Variant links:
Genes affected
AGRN (HGNC:329): (agrin) This gene encodes one of several proteins that are critical in the development of the neuromuscular junction (NMJ), as identified in mouse knock-out studies. The encoded protein contains several laminin G, Kazal type serine protease inhibitor, and epidermal growth factor domains. Additional post-translational modifications occur to add glycosaminoglycans and disulfide bonds. In one family with congenital myasthenic syndrome affecting limb-girdle muscles, a mutation in this gene was found. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Mar 2015]
AGRN Gene-Disease associations (from GenCC):
  • congenital myasthenic syndrome 8
    Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • presynaptic congenital myasthenic syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • postsynaptic congenital myasthenic syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
AGRNNM_198576.4 linkc.904G>A p.Ala302Thr missense_variant Exon 5 of 36 ENST00000379370.7 NP_940978.2 O00468-6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
AGRNENST00000379370.7 linkc.904G>A p.Ala302Thr missense_variant Exon 5 of 36 1 NM_198576.4 ENSP00000368678.2 O00468-6

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151998
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
7.26e-7
AC:
1
AN:
1377006
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
679978
show subpopulations
⚠️ 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:
31032
American (AMR)
AF:
0.00
AC:
0
AN:
33870
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24298
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35924
South Asian (SAS)
AF:
0.00
AC:
0
AN:
78338
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
33694
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5644
European-Non Finnish (NFE)
AF:
9.29e-7
AC:
1
AN:
1076798
Other (OTH)
AF:
0.00
AC:
0
AN:
57408
⚠️ 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.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.325
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00000658
AC:
1
AN:
151998
Hom.:
0
Cov.:
31
AF XY:
0.0000135
AC XY:
1
AN XY:
74236
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41412
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5168
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10582
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
312
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67950
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Congenital myasthenic syndrome 8 Uncertain:1
Oct 03, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 302 of the AGRN protein (p.Ala302Thr). This variant is present in population databases (no rsID available, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with AGRN-related conditions. ClinVar contains an entry for this variant (Variation ID: 541167). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.54
BayesDel_addAF
Benign
-0.094
T
BayesDel_noAF
Benign
-0.37
CADD
Uncertain
25
DANN
Uncertain
1.0
Eigen
Uncertain
0.51
Eigen_PC
Uncertain
0.38
FATHMM_MKL
Uncertain
0.88
D
LIST_S2
Uncertain
0.87
D;D
M_CAP
Uncertain
0.19
D
MetaRNN
Uncertain
0.65
D;D
MetaSVM
Benign
-1.1
T
MutationAssessor
Uncertain
2.6
M;.
PhyloP100
5.2
PrimateAI
Uncertain
0.73
T
PROVEAN
Uncertain
-2.4
N;.
REVEL
Benign
0.26
Sift
Uncertain
0.0080
D;.
Sift4G
Uncertain
0.053
T;T
Vest4
0.42
MutPred
0.53
Gain of relative solvent accessibility (P = 0.1259);.;
MVP
0.73
MPC
1.1
ClinPred
0.97
D
GERP RS
4.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.9
gMVP
0.63
Mutation Taster
=71/29
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: rs1318084676; hg19: chr1-976729; COSMIC: COSV65070872; COSMIC: COSV65070872; API