NM_000426.4:c.4487C>T

Variant names:

• chr6-129349348-C-T
• rs147077184
• NM_000426.4:c.4487C>T

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 2P and 12B. PM1 BP4_Strong BS1 BS2

The NM_000426.4(LAMA2):​c.4487C>T​(p.Ala1496Val) variant causes a missense change. The variant allele was found at a frequency of 0.00368 in 1,613,554 control chromosomes in the GnomAD database, including 32 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0033 (1 hom., cov: 32)
  • Exomes 𝑓: 0.0037 (31 hom.)
• Consequence: LAMA2 NM_000426.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:5 B:11 O:1
• Conservation: PhyloP100: 4.30

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 Benign. Variant got -10 ACMG points.

• PM1: In a domain Laminin EGF-like 16 (size 57) in uniprot entity LAMA2_HUMAN there are 5 pathogenic changes around while only 2 benign (71%) in NM_000426.4
• BP4: Computational evidence support a benign effect (MetaRNN=0.032247603).
• BS1: Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.00335 (510/152248) while in subpopulation AMR AF= 0.00504 (77/15276). AF 95% confidence interval is 0.00413. There are 1 homozygotes in gnomad4. There are 231 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High Homozygotes in GnomAdExome4 at 31 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMA2	NM_000426.4	c.4487C>T	p.Ala1496Val	missense_variant	Exon 31 of 65	ENST00000421865.3	NP_000417.3
LAMA2	NM_001079823.2	c.4487C>T	p.Ala1496Val	missense_variant	Exon 31 of 64		NP_001073291.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA2	ENST00000421865.3	c.4487C>T	p.Ala1496Val	missense_variant	Exon 31 of 65	5	NM_000426.4	ENSP00000400365.2

Frequencies

GnomAD3 genomes AF: 0.00335 AC: 509 AN: 152130 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.000652

Gnomad AMI AF: 0.00768

Gnomad AMR AF: 0.00505

Gnomad ASJ AF: 0.0253

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00273

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.00390

Gnomad OTH AF: 0.00670

GnomAD3 exomes AF: 0.00373 AC: 937 AN: 251380 Hom.: 5 AF XY: 0.00384 AC XY: 521 AN XY: 135850

Gnomad AFR exome AF: 0.000554

Gnomad AMR exome AF: 0.00260

Gnomad ASJ exome AF: 0.0221

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000229

Gnomad FIN exome AF: 0.00402

Gnomad NFE exome AF: 0.00429

Gnomad OTH exome AF: 0.00538

GnomAD4 exome AF: 0.00371 AC: 5424 AN: 1461306 Hom.: 31 Cov.: 30 AF XY: 0.00364 AC XY: 2649 AN XY: 726982

Gnomad4 AFR exome AF: 0.000747

Gnomad4 AMR exome AF: 0.00297

Gnomad4 ASJ exome AF: 0.0238

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000325

Gnomad4 FIN exome AF: 0.00328

Gnomad4 NFE exome AF: 0.00374

Gnomad4 OTH exome AF: 0.00446

GnomAD4 genome AF: 0.00335 AC: 510 AN: 152248 Hom.: 1 Cov.: 32 AF XY: 0.00310 AC XY: 231 AN XY: 74440

Gnomad4 AFR AF: 0.000650

Gnomad4 AMR AF: 0.00504

Gnomad4 ASJ AF: 0.0253

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00273

Gnomad4 NFE AF: 0.00391

Gnomad4 OTH AF: 0.00664

Alfa AF: 0.00418 Hom.: 6

Bravo AF: 0.00342

TwinsUK AF: 0.00405 AC: 15

ALSPAC AF: 0.00337 AC: 13

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00442 AC: 38

ExAC AF: 0.00334 AC: 406

Asia WGS AF: 0.00231 AC: 8 AN: 3478

EpiCase AF: 0.00507

EpiControl AF: 0.00605

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:5 Benign:11 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:5

Jun 09, 2016

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

-

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Dec 15, 2017

Athena Diagnostics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

LAMA2: BS2 -

Apr 03, 2018

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is associated with the following publications: (PMID: 24957499, 28133863, 27854218) -

not specified Uncertain:2 Benign:2

Dec 07, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: LAMA2 c.4487C>T (p.Ala1496Val) results in a non-conservative amino acid change located in the EGF-like domain (IPR000742) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.0037 in 1613554 control chromosomes in the gnomAD database V4, including 32 homozygotes. The observed variant frequency is approximately 2 fold of the estimated maximal expected allele frequency for a pathogenic variant in LAMA2 causing Laminin Alpha 2-Related Dystrophy phenotype (0.0022), strongly suggesting that the variant is benign. Although reported in mutational updates (example, Oliviera_2018), to our knowledge, no penetrant association of c.4487C>T in individuals affected with Laminin Alpha 2-Related Dystrophy and no supporting experimental evidence demonstrating its impact on protein function have been reported. The following publication has been ascertained in the context of this evaluation (PMID: 30055037). Nine submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as benign/likely benign (n=5) and VUS (n=4). Based on the evidence outlined above, the variant was classified as likely benign. -

Dec 01, 2015

Center for Genetic Medicine Research, Children's National Medical Center

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: research

- -

-

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Dec 01, 2014

Genetic Services Laboratory, University of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Merosin deficient congenital muscular dystrophy Uncertain:1 Benign:1 Other:1

-

GenomeConnect, ClinGen

Significance: not provided

Review Status: no classification provided

Collection Method: phenotyping only

GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -

Jun 01, 2017

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 22, 2023

Mendelics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Muscular dystrophy, limb-girdle, autosomal recessive 23 Pathogenic:1 Benign:1

Oct 05, 2018

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

May 04, 2023

Molecular Genetics, Royal Melbourne Hospital

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

European Non-Finnish population allele frequency is 0.3978%% (rs147077184, 937/251380 alleles, 5 homozygotes in gnomAD v2.1). Based on the classification scheme RMH Modified ACMG/AMP Guidelines v1.5.1, this variant is classified as LIKELY BENIGN. Following criteria are met: BS1 -

Congenital muscular dystrophy due to partial LAMA2 deficiency Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

LAMA2-related muscular dystrophy Benign:1

Jan 28, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

LAMA2-related disorder Benign:1

Dec 31, 2019

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.10
CADD	Benign	23
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.034	.;T;T
Eigen	Uncertain	0.31
Eigen_PC	Benign	0.22
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.88	D;D;D
M_CAP	Uncertain	0.090	D
MetaRNN	Benign	0.032	T;T;T
MetaSVM	Benign	-0.55	T
MutationAssessor	Benign	1.9	.;.;L
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-3.3	.;.;D
REVEL	Pathogenic	0.71
Sift	Uncertain	0.0080	.;.;D
Polyphen		0.99	.;.;D
Vest4		0.68
MVP		0.75
MPC		0.37
ClinPred		0.015	T
GERP RS		5.1
Varity_R		0.36
gMVP		0.47

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs147077184; hg19: chr6-129670493; COSMIC: COSV70352704;