dbSNP rs1554300251: LAMA2:p.Ala2253Thr (chr6-129456384-G-A) – ACMG Classification: Uncertain_significance (1 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4

The NM_000426.4(LAMA2):c.6757G>A(p.Ala2253Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,402 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A2253V) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 6.11

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:

ENSG00000226149 (HGNC:):

ENSG00000226149 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.34672987).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMA2	NM_000426.4 link	c.6757G>A	p.Ala2253Thr	missense_variant	Exon 48 of 65	ENST00000421865.3	NP_000417.3
LAMA2	NM_001079823.2 link	c.6757G>A	p.Ala2253Thr	missense_variant	Exon 48 of 64		NP_001073291.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA2	ENST00000421865.3 link	c.6757G>A	p.Ala2253Thr	missense_variant	Exon 48 of 65	5	NM_000426.4	ENSP00000400365.2		P24043

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461402

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727010

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

33444

American (AMR)

AF:

0.00

AC:

AN:

44690

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26110

East Asian (EAS)

AF:

0.00

AC:

AN:

39678

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

9.00e-7

AC:

AN:

1111678

Other (OTH)

AF:

0.00

AC:

AN:

60366

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

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.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

0.0067

BayesDel_noAF

Benign

-0.23

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.014

.;T;T

Eigen

Uncertain

0.58

Eigen_PC

Uncertain

0.62

FATHMM_MKL

Uncertain

0.97

LIST_S2

Benign

0.86

D;D;D

M_CAP

Benign

0.048

MetaRNN

Benign

0.35

T;T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

0.95

.;.;L

PhyloP100

6.1

PrimateAI

Uncertain

0.56

PROVEAN

Benign

-0.32

.;.;N

REVEL

Benign

0.28

Sift

Benign

0.18

.;.;T

Polyphen

1.0

.;.;D

Vest4

0.46

MutPred

0.35

.;Gain of glycosylation at A2253 (P = 0.1489);Gain of glycosylation at A2253 (P = 0.1489);

MVP

0.71

MPC

0.40

ClinPred

0.98

GERP RS

5.5

Varity_R

0.17

gMVP

0.54

Mutation Taster

=46/54

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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

Computational scores

Splicing

Publications

Other links and lift over