chr6-129291700-C-T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000426.4(LAMA2):​c.2836C>T​(p.Gln946*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,226 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 Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Q946Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 stop_gained

Scores

2
2
3

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2

Conservation

PhyloP100: 0.868

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: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 6-129291700-C-T is Pathogenic according to our data. Variant chr6-129291700-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 477458.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMA2NM_000426.4 linkc.2836C>T p.Gln946* stop_gained Exon 20 of 65 ENST00000421865.3 NP_000417.3
LAMA2NM_001079823.2 linkc.2836C>T p.Gln946* stop_gained Exon 20 of 64 NP_001073291.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMA2ENST00000421865.3 linkc.2836C>T p.Gln946* stop_gained Exon 20 of 65 5 NM_000426.4 ENSP00000400365.2 P24043
LAMA2ENST00000618192.5 linkc.2836C>T p.Gln946* stop_gained Exon 20 of 66 5 ENSP00000480802.2 A0A087WX80
LAMA2ENST00000617695.5 linkc.2836C>T p.Gln946* stop_gained Exon 20 of 64 5 ENSP00000481744.2 A0A087WYF1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152156
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461070
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
726898
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33468
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39686
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86216
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
9.00e-7
AC:
1
AN:
1111308
Other (OTH)
AF:
0.00
AC:
0
AN:
60360
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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:
0.0000131
AC:
2
AN:
152156
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74346
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41422
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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:
0.0000264
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Merosin deficient congenital muscular dystrophy Pathogenic:1
Sep 26, 2023
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

LAMA2-related muscular dystrophy Pathogenic:1
Feb 24, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal at codon 946 (p.Gln946*) of the LAMA2 gene. It is expected to result in an absent or disrupted protein product. While this particular variant has not been reported in the literature, loss-of-function variants in LAMA2 are known to be pathogenic (PMID: 18700894). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
34
DANN
Uncertain
1.0
Eigen
Uncertain
0.26
Eigen_PC
Benign
-0.070
FATHMM_MKL
Benign
0.20
N
PhyloP100
0.87
Vest4
0.88
GERP RS
3.7
Mutation Taster
=1/199
disease causing (ClinVar)

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: rs375638381; hg19: chr6-129612845; API