rs367665458

Positions:

• chr6-129454240-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000426.4(LAMA2):​c.6659C>T​(p.Pro2220Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000658 in 152,002 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: LAMA2 NM_000426.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.85

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]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.826

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LAMA2	NM_000426.4	c.6659C>T	p.Pro2220Leu	missense_variant	47/65	ENST00000421865.3	NP_000417.3
LAMA2	NM_001079823.2	c.6659C>T	p.Pro2220Leu	missense_variant	47/64		NP_001073291.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LAMA2	ENST00000421865.3	c.6659C>T	p.Pro2220Leu	missense_variant	47/65	5	NM_000426.4	ENSP00000400365
	ENST00000665046.1	n.976-12988G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152002 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 29

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152002 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74236

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jul 12, 2017

- -

LAMA2-related muscular dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 16, 2022

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 2220 of the LAMA2 protein (p.Pro2220Leu). This variant is not present in population databases (gnomAD no frequency). 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: 447690). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.070
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.079	.;T;T
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Uncertain	0.093	D
MetaRNN	Pathogenic	0.83	D;D;D
MetaSVM	Benign	-0.76	T
MutationAssessor	Benign	1.8	.;.;L
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-7.5	.;.;D
REVEL	Uncertain	0.45
Sift	Uncertain	0.0010	.;.;D
Polyphen		1.0	.;.;D
Vest4		0.73
MVP		0.80
MPC		0.48
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.65
gMVP		0.70

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

LitVar

Other links and lift over

dbSNP: rs367665458; hg19: chr6-129775385;