chr6-129473259-T-C

Variant summary

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

The NM_000426.4(LAMA2):​c.7346T>C​(p.Ile2449Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000373 in 1,607,626 control chromosomes in the GnomAD database, with no homozygous occurrence. 13/22 in silico tools predict 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. I2449M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 missense

Scores

1
4
13

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 6.69

Publications

1 publications found
Variant links:
Genes affected
LAMA2 (HGNC:6482): (laminin subunit alpha 2) Laminin, an extracellular protein, is a major component of the basement membrane. It is thought to mediate the attachment, migration, and organization of cells into tissues during embryonic development by interacting with other extracellular matrix components. It is composed of three subunits, alpha, beta, and gamma, which are bound to each other by disulfide bonds into a cross-shaped molecule. This gene encodes the alpha 2 chain, which constitutes one of the subunits of laminin 2 (merosin) and laminin 4 (s-merosin). Mutations in this gene have been identified as the cause of congenital merosin-deficient muscular dystrophy. Two transcript variants encoding different proteins have been found for this gene. [provided by RefSeq, Jul 2008]
LAMA2 Gene-Disease associations (from GenCC):
  • congenital merosin-deficient muscular dystrophy 1A
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, G2P
  • LAMA2-related muscular dystrophy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • muscular dystrophy, limb-girdle, autosomal recessive 23
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)

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
LAMA2NM_000426.4 linkc.7346T>C p.Ile2449Thr missense_variant Exon 52 of 65 ENST00000421865.3 NP_000417.3
LAMA2NM_001079823.2 linkc.7346T>C p.Ile2449Thr missense_variant Exon 52 of 64 NP_001073291.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMA2ENST00000421865.3 linkc.7346T>C p.Ile2449Thr missense_variant Exon 52 of 65 5 NM_000426.4 ENSP00000400365.2 P24043
LAMA2ENST00000618192.5 linkc.7610T>C p.Ile2537Thr missense_variant Exon 53 of 66 5 ENSP00000480802.2 A0A087WX80
LAMA2ENST00000617695.5 linkc.7346T>C p.Ile2449Thr missense_variant Exon 52 of 64 5 ENSP00000481744.2 A0A087WYF1
ENSG00000226149ENST00000665046.1 linkn.975+29346A>G intron_variant Intron 9 of 9

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152032
Hom.:
0
Cov.:
32
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:
0.00000344
AC:
5
AN:
1455594
Hom.:
0
Cov.:
29
AF XY:
0.00000276
AC XY:
2
AN XY:
724564
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33330
American (AMR)
AF:
0.00
AC:
0
AN:
44670
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26060
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39530
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86102
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53262
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5744
European-Non Finnish (NFE)
AF:
0.00000452
AC:
5
AN:
1106800
Other (OTH)
AF:
0.00
AC:
0
AN:
60096
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.445
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

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:
152032
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74242
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41442
American (AMR)
AF:
0.00
AC:
0
AN:
15226
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67934
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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

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:
0.00
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Oct 31, 2016
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

LAMA2-related muscular dystrophy Uncertain:1
Jan 12, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 2449 of the LAMA2 protein (p.Ile2449Thr). 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 LAMA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 447692). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt LAMA2 protein function. 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
Benign
0.10
BayesDel_addAF
Benign
-0.062
T
BayesDel_noAF
Benign
-0.33
CADD
Benign
23
DANN
Uncertain
0.98
DEOGEN2
Benign
0.018
.;T;T
Eigen
Benign
0.16
Eigen_PC
Uncertain
0.29
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.81
T;T;T
M_CAP
Benign
0.058
D
MetaRNN
Uncertain
0.58
D;D;D
MetaSVM
Benign
-0.79
T
MutationAssessor
Benign
1.0
.;.;L
PhyloP100
6.7
PrimateAI
Uncertain
0.49
T
PROVEAN
Benign
-0.57
.;.;N
REVEL
Benign
0.20
Sift
Benign
0.073
.;.;T
Polyphen
0.57
.;.;P
Vest4
0.54
MutPred
0.49
.;Loss of stability (P = 0.0304);Loss of stability (P = 0.0304);
MVP
0.85
MPC
0.23
ClinPred
0.60
D
GERP RS
6.1
Varity_R
0.17
gMVP
0.46
Mutation Taster
=66/34
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs1156828795; hg19: chr6-129794404; API