NM_000426.4:c.6955C>T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000426.4(LAMA2):​c.6955C>T​(p.Arg2319*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000242 in 1,611,908 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 (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 stop_gained

Scores

4
2
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 4.19
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 6-129460287-C-T is Pathogenic according to our data. Variant chr6-129460287-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 92980.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr6-129460287-C-T is described in Lovd as [Pathogenic]. Variant chr6-129460287-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMA2NM_000426.4 linkc.6955C>T p.Arg2319* stop_gained Exon 49 of 65 ENST00000421865.3 NP_000417.3
LAMA2NM_001079823.2 linkc.6955C>T p.Arg2319* stop_gained Exon 49 of 64 NP_001073291.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMA2ENST00000421865.3 linkc.6955C>T p.Arg2319* stop_gained Exon 49 of 65 5 NM_000426.4 ENSP00000400365.2 P24043

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151800
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
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
GnomAD3 exomes
AF:
0.0000160
AC:
4
AN:
250586
Hom.:
0
AF XY:
0.0000148
AC XY:
2
AN XY:
135416
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000354
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000253
AC:
37
AN:
1460108
Hom.:
0
Cov.:
31
AF XY:
0.0000262
AC XY:
19
AN XY:
726424
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000306
Gnomad4 OTH exome
AF:
0.0000332
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
151800
Hom.:
0
Cov.:
32
AF XY:
0.0000270
AC XY:
2
AN XY:
74110
show subpopulations
Gnomad4 AFR
AF:
0.0000242
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000577
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.0000546
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Merosin deficient congenital muscular dystrophy Pathogenic:5
Sep 01, 2022
3billion
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.002%). Stop-gained (nonsense) is predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000092980 / PMID: 9674786 / 3billion dataset). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

-
Neuberg Centre For Genomic Medicine, NCGM
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The stop gained c.6955C>T p.Arg2319Ter variant in LAMA2 gene has been previously reported in homozygous and compound heterozygous states in multiple individuals affected with muscular dystrophy Pegoraro et al., 1998; Kim et al., 2017. The p.Arg2319Ter variant has been reported with allele frequency of 0.001% in gnomAD Exomes and is novel not in any individuals in 1000 Genomes. This variant has been reported to the ClinVar database as Likely Pathogenic / Pathogenic multiple submissions. The nucleotide change c.6955C>T in LAMA2 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. This sequence change creates a premature translational stop signal p.Arg2319Ter in the LAMA2 gene. This variant is predicted to cause loss of normal protein function through protein truncation. Loss of function variants in LAMA2 gene have been previously reported to be pathogenic Magri et al., 2020. For these reasons, this variant has been classified as Pathogenic. -

-
Service de Génétique Moléculaire, Hôpital Robert Debré
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Apr 07, 2017
Counsyl
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Mar 27, 2024
Baylor Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not provided Pathogenic:3
Mar 30, 2022
Revvity Omics, Revvity
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 23, 2016
Eurofins Ntd Llc (ga)
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 01, 2021
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at a significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 29465610, 25525159, 11369186, 32936536, 29376585, 9674786, 28445022, 30055037) -

Myalgia;C0241005:Elevated circulating creatine kinase concentration;C1850830:Exercise-induced myalgia Pathogenic:1
Jan 01, 2017
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

LAMA2-related muscular dystrophy Pathogenic:1
Nov 06, 2024
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 (p.Arg2319*) in the LAMA2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in LAMA2 are known to be pathogenic (PMID: 18700894, 32904964). This variant is present in population databases (rs398123383, gnomAD 0.004%). This premature translational stop signal has been observed in individuals with congenital muscular dystrophy (PMID: 9674786, 28445022, 30055037). This variant is also known as c.7004C>T. ClinVar contains an entry for this variant (Variation ID: 92980). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.55
D
BayesDel_noAF
Pathogenic
0.63
CADD
Pathogenic
43
DANN
Uncertain
1.0
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Uncertain
0.95
D
Vest4
0.96
GERP RS
6.0

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.090
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs398123383; hg19: chr6-129781432; COSMIC: COSV70341208; API