rs186538779

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_ModeratePP5_Moderate

The NM_000426.4(LAMA2):​c.2461A>C​(p.Thr821Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000496 in 1,612,354 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 Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T821M) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 missense

Scores

8
6
4

Clinical Significance

Pathogenic criteria provided, single submitter P:2

Conservation

PhyloP100: 5.62

Publications

13 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: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.881
PP5
Variant 6-129280071-A-C is Pathogenic according to our data. Variant chr6-129280071-A-C is described in ClinVar as Pathogenic. ClinVar VariationId is 242608.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMA2NM_000426.4 linkc.2461A>C p.Thr821Pro missense_variant Exon 18 of 65 ENST00000421865.3 NP_000417.3
LAMA2NM_001079823.2 linkc.2461A>C p.Thr821Pro missense_variant Exon 18 of 64 NP_001073291.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMA2ENST00000421865.3 linkc.2461A>C p.Thr821Pro missense_variant Exon 18 of 65 5 NM_000426.4 ENSP00000400365.2
LAMA2ENST00000618192.5 linkc.2461A>C p.Thr821Pro missense_variant Exon 18 of 66 5 ENSP00000480802.2
LAMA2ENST00000617695.5 linkc.2461A>C p.Thr821Pro missense_variant Exon 18 of 64 5 ENSP00000481744.2

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152136
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.00000411
AC:
6
AN:
1460218
Hom.:
0
Cov.:
30
AF XY:
0.00000275
AC XY:
2
AN XY:
726522
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33424
American (AMR)
AF:
0.00
AC:
0
AN:
44608
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26110
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86234
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1110662
Other (OTH)
AF:
0.00
AC:
0
AN:
60322
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
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:
0.0000131
AC:
2
AN:
152136
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74316
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41434
American (AMR)
AF:
0.0000655
AC:
1
AN:
15258
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.650
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:2
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Merosin deficient congenital muscular dystrophy Pathogenic:1
Feb 15, 2018
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

LAMA2-related muscular dystrophy Pathogenic:1
Jul 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with proline, which is neutral and non-polar, at codon 821 of the LAMA2 protein (p.Thr821Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with LAMA2-related muscular dystrophy (PMID: 24534542, 27858741, 30055037). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 242608). 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 with a negative predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.41
BayesDel_addAF
Pathogenic
0.18
D
BayesDel_noAF
Uncertain
0.020
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Benign
0.065
.;T;T
Eigen
Pathogenic
0.71
Eigen_PC
Pathogenic
0.67
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.81
T;T;T
M_CAP
Uncertain
0.18
D
MetaRNN
Pathogenic
0.88
D;D;D
MetaSVM
Uncertain
-0.21
T
MutationAssessor
Pathogenic
4.1
.;.;H
PhyloP100
5.6
PrimateAI
Benign
0.27
T
PROVEAN
Pathogenic
-4.8
.;.;D
REVEL
Pathogenic
0.82
Sift
Uncertain
0.0020
.;.;D
Polyphen
1.0
.;.;D
Vest4
0.62
MutPred
0.62
Gain of catalytic residue at P820 (P = 0.0126);Gain of catalytic residue at P820 (P = 0.0126);Gain of catalytic residue at P820 (P = 0.0126);
MVP
0.87
MPC
0.53
ClinPred
1.0
D
GERP RS
5.7
Varity_R
0.94
gMVP
0.69
Mutation Taster
=12/88
disease causing (ClinVar)

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: rs186538779; hg19: chr6-129601216; API