rs376437110

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_000426.4(LAMA2):​c.745C>T​(p.Arg249Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,612,472 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R249H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 missense

Scores

12
4
1

Clinical Significance

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

Conservation

PhyloP100: 1.11

Publications

5 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 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.902

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000426.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
LAMA2
NM_000426.4
MANE Select
c.745C>Tp.Arg249Cys
missense
Exon 5 of 65NP_000417.3
LAMA2
NM_001079823.2
c.745C>Tp.Arg249Cys
missense
Exon 5 of 64NP_001073291.2

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
LAMA2
ENST00000421865.3
TSL:5 MANE Select
c.745C>Tp.Arg249Cys
missense
Exon 5 of 65ENSP00000400365.2
LAMA2
ENST00000618192.5
TSL:5
c.745C>Tp.Arg249Cys
missense
Exon 5 of 66ENSP00000480802.2
LAMA2
ENST00000617695.5
TSL:5
c.745C>Tp.Arg249Cys
missense
Exon 5 of 64ENSP00000481744.2

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
151880
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:
0.0000589
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000798
AC:
2
AN:
250766
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000177
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000959
AC:
14
AN:
1460592
Hom.:
0
Cov.:
31
AF XY:
0.0000151
AC XY:
11
AN XY:
726616
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33422
American (AMR)
AF:
0.00
AC:
0
AN:
44598
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26072
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39672
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86238
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53398
Middle Eastern (MID)
AF:
0.000174
AC:
1
AN:
5758
European-Non Finnish (NFE)
AF:
0.00000990
AC:
11
AN:
1111118
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60316
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.443
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000263
AC:
4
AN:
151880
Hom.:
0
Cov.:
32
AF XY:
0.0000270
AC XY:
2
AN XY:
74190
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41372
American (AMR)
AF:
0.00
AC:
0
AN:
15208
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4814
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10600
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000589
AC:
4
AN:
67928
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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:
0.0000660
Hom.:
0
Bravo
AF:
0.0000227
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000165
AC:
2

ClinVar

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

Submissions by phenotype

not provided Uncertain:2
Jul 13, 2021
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Sep 09, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported with a second LAMA2 variant, phase unknown, in a patient with a congenital muscular dystrophy phenotype (PMID: 30055037); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 30055037)

LAMA2-related muscular dystrophy Uncertain:1
Apr 29, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 249 of the LAMA2 protein (p.Arg249Cys). This variant is present in population databases (rs376437110, gnomAD 0.003%). This missense change has been observed in individual(s) with congenital muscular dystrophy (PMID: 30055037). ClinVar contains an entry for this variant (Variation ID: 477505). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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 v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.95
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.28
CADD
Pathogenic
32
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.078
T
Eigen
Pathogenic
0.70
Eigen_PC
Uncertain
0.64
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Uncertain
0.16
D
MetaRNN
Pathogenic
0.90
D
MetaSVM
Uncertain
0.42
D
MutationAssessor
Pathogenic
3.1
M
PhyloP100
1.1
PrimateAI
Pathogenic
0.89
D
PROVEAN
Pathogenic
-7.5
D
REVEL
Pathogenic
0.73
Sift
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.87
MVP
0.88
MPC
0.56
ClinPred
1.0
D
GERP RS
5.4
Varity_R
0.89
gMVP
0.71
Mutation Taster
=36/64
disease causing

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: rs376437110; hg19: chr6-129465151; COSMIC: COSV70346446; API