chr6-129464288-A-C

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.6993-2A>C variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000559 in 1,610,460 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

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

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 8.83

Publications

2 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: Labcorp Genetics (formerly Invitae), Orphanet, G2P, Myriad Women’s Health
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:

ENSG00000226149 (HGNC:):

ENSG00000226149 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 13, offset of 7, new splice context is: tctctcttctccgtcctcAGgtg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 6-129464288-A-C is Pathogenic according to our data. Variant chr6-129464288-A-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 551050.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMA2	NM_000426.4	MANE Select	c.6993-2A>C		splice_acceptor intron	N/A	NP_000417.3
	LAMA2	NM_001079823.2		c.6993-2A>C		splice_acceptor intron	N/A	NP_001073291.2	A0A087WYF1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein	UniProt
LAMA2	ENST00000421865.3	TSL:5 MANE Select	c.6993-2A>C	splice_acceptor intron	N/A	ENSP00000400365.2	P24043
LAMA2	ENST00000618192.5	TSL:5	c.7257-2A>C	splice_acceptor intron	N/A	ENSP00000480802.2	A0A087WX80
LAMA2	ENST00000617695.5	TSL:5	c.6993-2A>C	splice_acceptor intron	N/A	ENSP00000481744.2	A0A087WYF1

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

151970

Hom.:

Cov.:

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000160

AC:

AN:

250742

AF XY:

0.0000221

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:

0.0000353

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000480

AC:

AN:

1458490

Hom.:

Cov.:

AF XY:

0.00000276

AC XY:

AN XY:

725772

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33330

American (AMR)

AF:

0.00

AC:

AN:

44596

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26038

East Asian (EAS)

AF:

0.00

AC:

AN:

39642

South Asian (SAS)

AF:

0.00

AC:

AN:

86206

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53398

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5744

European-Non Finnish (NFE)

AF:

0.00000631

AC:

AN:

1109302

Other (OTH)

AF:

0.00

AC:

AN:

60234

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.461

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

AF:

0.0000132

AC:

AN:

151970

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74232

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41416

American (AMR)

AF:

0.00

AC:

AN:

15220

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3462

East Asian (EAS)

AF:

0.00

AC:

AN:

5158

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

67936

Other (OTH)

AF:

0.00

AC:

AN:

2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.400

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.0000359

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000165

AC:

ClinVar

ClinVar submissions

Significance:Pathogenic/Likely pathogenic

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

LAMA2-related muscular dystrophy (1)

Merosin deficient congenital muscular dystrophy (1)

Merosin deficient congenital muscular dystrophy;C4748327:Muscular dystrophy, limb-girdle, autosomal recessive 23 (1)

not provided (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.55

BayesDel_noAF

Pathogenic

0.28

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.99

PhyloP100

8.8

GERP RS

5.9

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.70

Position offset: 9

DS_AL_spliceai

0.98

Position offset: 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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over