rs1209130981

Variant names:

Variant summary

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

The NM_000426.4(LAMA2):c.939_940delAT(p.Cys314TrpfsTer3) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000548 in 1,461,136 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 5.85

Publications

0 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)

LAMA2 links:

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 6-129149007-CAT-C is Pathogenic according to our data. Variant chr6-129149007-CAT-C is described in ClinVar as Pathogenic. ClinVar VariationId is 477529.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
LAMA2	NM_000426.4 link	c.939_940delAT	p.Cys314TrpfsTer3	frameshift_variant	Exon 7 of 65	ENST00000421865.3	NP_000417.3
LAMA2	NM_001079823.2 link	c.939_940delAT	p.Cys314TrpfsTer3	frameshift_variant	Exon 7 of 64		NP_001073291.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA2	ENST00000421865.3 link	c.939_940delAT	p.Cys314TrpfsTer3	frameshift_variant	Exon 7 of 65	5	NM_000426.4	ENSP00000400365.2		P24043

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000279

AC:

AN:

251318

AF XY:

0.0000221

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000202

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000548

AC:

AN:

1461136

Hom.:

AF XY:

0.00000550

AC XY:

AN XY:

726926

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33448

American (AMR)

AF:

0.000179

AC:

AN:

44714

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26116

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86242

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111360

Other (OTH)

AF:

0.00

AC:

AN:

60376

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.488

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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

Cov.:

Alfa

AF:

0.0000936

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

LAMA2-related muscular dystrophy

Pathogenic:3

Jan 15, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: LAMA2 c.939_940delAT (p.Cys314TrpfsX3) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 2.8e-05 in 251318 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.939_940delAT has been reported in the literature in multiple homozygous and compound heterozygous individuals affected with Laminin Alpha 2-Related Dystrophy (e.g., Oliveira_2018). These data indicate that the variant is very likely to be associated with disease. The following publication have been ascertained in the context of this evaluation (PMID: 30055037). ClinVar contains an entry for this variant (Variation ID: 477529). Based on the evidence outlined above, the variant was classified as pathogenic. -

Aug 08, 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.Cys314Trpfs*3) 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 (no rsID available, gnomAD 0.02%). This premature translational stop signal has been observed in individuals with congenital muscular dystrophy (PMID: 30055037). ClinVar contains an entry for this variant (Variation ID: 477529). For these reasons, this variant has been classified as Pathogenic. -

Oct 10, 2024

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Based on the classification scheme VCGS_Germline_v1.3.5, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with LAMA2-related muscular dystrophy (MONDO:0100228). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0201 - Variant is predicted to cause nonsense-mediated decay (NMD) and loss of protein (premature termination codon is located at least 54 nucleotides upstream of the final exon-exon junction). (SP) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v4) <0.01 for a recessive condition (8 heterozygotes, 0 homozygotes). (SP) 0701 - Other NMD-predicted variants comparable to the one identified in this case have very strong previous evidence for pathogenicity (DECIPHER). (SP) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been reported five times as pathogenic, and once as likely pathogenic in ClinVar by clinical laboratories. This variant has been observed in multiple individuals with congenital muscular dystrophy, type 1A (MDC1A) (PMID: 30055037). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Merosin deficient congenital muscular dystrophy

Pathogenic:2

Mar 22, 2017

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. -

Mar 29, 2024

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Inborn genetic diseases

Pathogenic:1

Sep 22, 2017

Ambry Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Pathogenic:1

Feb 24, 2021

Revvity Omics, Revvity

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

5.8

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.11

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over