6-129146969-C-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5

The NM_000426.4(LAMA2):c.830C>T(p.Ser277Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000106 in 1,607,586 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S277W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:4

Conservation

PhyloP100: 7.79

Publications

7 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: Likely_pathogenic. The variant received 7 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.973

PP5

Variant 6-129146969-C-T is Pathogenic according to our data. Variant chr6-129146969-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 92990.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMA2	NM_000426.4 link	c.830C>T	p.Ser277Leu	missense_variant	Exon 6 of 65	ENST00000421865.3	NP_000417.3
LAMA2	NM_001079823.2 link	c.830C>T	p.Ser277Leu	missense_variant	Exon 6 of 64		NP_001073291.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA2	ENST00000421865.3 link	c.830C>T	p.Ser277Leu	missense_variant	Exon 6 of 65	5	NM_000426.4	ENSP00000400365.2		P24043

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152038

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.000480

GnomAD2 exomes

AF:

0.00000798

AC:

AN:

250744

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000884

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000824

AC:

AN:

1455548

Hom.:

Cov.:

AF XY:

0.00000828

AC XY:

AN XY:

724442

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33298

American (AMR)

AF:

0.0000224

AC:

AN:

44658

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26042

East Asian (EAS)

AF:

0.00

AC:

AN:

39674

South Asian (SAS)

AF:

0.00

AC:

AN:

86138

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53410

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5758

European-Non Finnish (NFE)

AF:

0.00000994

AC:

AN:

1106410

Other (OTH)

AF:

0.00

AC:

AN:

60160

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.433

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:

0.0000329

AC:

AN:

152038

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74280

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41410

American (AMR)

AF:

0.00

AC:

AN:

15248

Ashkenazi Jewish (ASJ)

AF:

0.000288

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10604

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

67972

Other (OTH)

AF:

0.000480

AC:

AN:

2084

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

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:

0.00

Hom.:

Bravo

AF:

0.0000113

EpiCase

AF:

0.0000546

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Merosin deficient congenital muscular dystrophy

Pathogenic:1Uncertain:1

Oct 16, 2017

Counsyl

Significance:Uncertain significance

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. -

Jul 27, 2023

Baylor Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Uncertain:2

May 22, 2013

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Nov 06, 2019

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

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

Pathogenic:1

Apr 25, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Muscular dystrophy, limb-girdle, autosomal recessive 23

Pathogenic:1

Hadassah Hebrew University Medical Center

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

LAMA2-related muscular dystrophy

Uncertain:1

Aug 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 277 of the LAMA2 protein (p.Ser277Leu). This variant is present in population databases (rs398123388, gnomAD 0.01%). This missense change has been observed in individual(s) with LAMA2-related muscular dystrophy (PMID: 24225367). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 92990). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.97

BayesDel_addAF

Pathogenic

0.35

BayesDel_noAF

Pathogenic

0.35

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.070

.;T;D

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.95

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.97

D;D;D

M_CAP

Pathogenic

0.44

MetaRNN

Pathogenic

0.97

D;D;D

MetaSVM

Uncertain

0.54

MutationAssessor

Pathogenic

3.6

.;.;H

PhyloP100

7.8

PrimateAI

Uncertain

0.76

PROVEAN

Pathogenic

-5.3

.;.;D

REVEL

Pathogenic

0.96

Sift

Uncertain

0.0010

.;.;D

Polyphen

1.0

.;.;D

Vest4

0.97

MutPred

0.81

Gain of ubiquitination at K279 (P = 0.0683);Gain of ubiquitination at K279 (P = 0.0683);Gain of ubiquitination at K279 (P = 0.0683);

MVP

0.95

MPC

0.45

ClinPred

1.0

GERP RS

5.8

Varity_R

0.93

gMVP

0.92

Mutation Taster

=13/87

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.080

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

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over