rs766732392

chr6-129315581-A-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000426.4(LAMA2):c.3661A>G(p.Met1221Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000821 in 1,461,868 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1221R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: LAMA2 NM_000426.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.52

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.22979027).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMA2	NM_000426.4	c.3661A>G	p.Met1221Val	missense_variant	25/65	ENST00000421865.3
LAMA2	NM_001079823.2	c.3661A>G	p.Met1221Val	missense_variant	25/64

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMA2	ENST00000421865.3	c.3661A>G	p.Met1221Val	missense_variant	25/65	5	NM_000426.4
LAMA2	ENST00000618192.5	c.3925A>G	p.Met1309Val	missense_variant	26/66	5		P1
LAMA2	ENST00000617695.5	c.3661A>G	p.Met1221Val	missense_variant	25/64	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251480 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135914

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000109

Gnomad SAS 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: 0.00000821 AC: 12 AN: 1461868 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727240

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

LAMA2-related muscular dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 16, 2022

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1221 of the LAMA2 protein (p.Met1221Val). This variant is present in population databases (rs766732392, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with LAMA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 575902). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt LAMA2 protein function. 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Mar 20, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.091
BayesDel_addAF	Benign	-0.29	T
BayesDel_noAF	Benign	-0.43
Cadd	Benign	16
Dann	Benign	0.52
Eigen	Benign	-0.33
Eigen_PC	Benign	-0.15
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Benign	0.80	T;T;T
M_CAP	Benign	0.021	T
MetaRNN	Benign	0.23	T;T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	0.51	N
PrimateAI	Benign	0.40	T
Polyphen		0.024	.;.;B
Vest4		0.45
MutPred		0.56		Loss of disorder (P = 0.2587);Loss of disorder (P = 0.2587);Loss of disorder (P = 0.2587);
MVP		0.27
MPC		0.092
ClinPred		0.079	T
GERP RS		5.8
Varity_R		0.40
gMVP		0.49

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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

Other links and lift over

dbSNP: rs766732392; hg19: chr6-129636726; COSMIC: COSV70353786;