6-129267114-G-T

Variant names:

• chr6-129267114-G-T
• rs192317605
• NM_000426.4:c.2217G>T

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_Strong BP6 BS1 BS2

The NM_000426.4(LAMA2):​c.2217G>T​(p.Trp739Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00037 in 1,608,450 control chromosomes in the GnomAD database, including 3 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 0.00054 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00035 (3 hom.)
• Consequence: LAMA2 NM_000426.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:3
• Conservation: PhyloP100: 2.34
• Publications: 9 publications found

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)

ACMG classification

Our verdict: Benign. The variant received -13 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.011787742).
• BP6: Variant 6-129267114-G-T is Benign according to our data. Variant chr6-129267114-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 435712.
• BS1: Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000539 (82/152092) while in subpopulation EAS AF = 0.0122 (63/5154). AF 95% confidence interval is 0.00981. There are 0 homozygotes in GnomAd4. There are 48 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
• BS2: High Homozygotes in GnomAdExome4 at 3 AR gene

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000426.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMA2	NM_000426.4	MANE Select	c.2217G>T	p.Trp739Cys	missense	Exon 16 of 65	NP_000417.3
	LAMA2	NM_001079823.2		c.2217G>T	p.Trp739Cys	missense	Exon 16 of 64	NP_001073291.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMA2	ENST00000421865.3	TSL:5 MANE Select	c.2217G>T	p.Trp739Cys	missense	Exon 16 of 65	ENSP00000400365.2
	LAMA2	ENST00000618192.5	TSL:5	c.2217G>T	p.Trp739Cys	missense	Exon 16 of 66	ENSP00000480802.2
	LAMA2	ENST00000617695.5	TSL:5	c.2217G>T	p.Trp739Cys	missense	Exon 16 of 64	ENSP00000481744.2

Frequencies

GnomAD3 genomes AF: 0.000540 AC: 82 AN: 151974 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00260

Gnomad EAS AF: 0.0124

Gnomad SAS AF: 0.00145

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.000478

GnomAD2 exomes AF: 0.00105 AC: 264 AN: 251002 AF XY: 0.000966

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00208

Gnomad EAS exome AF: 0.0121

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000353

Gnomad OTH exome AF: 0.000816

GnomAD4 exome AF: 0.000352 AC: 513 AN: 1456358 Hom.: 3 Cov.: 30 AF XY: 0.000375 AC XY: 272 AN XY: 724864

African (AFR) AF: 0.00 AC: 0 AN: 33334

American (AMR) AF: 0.00 AC: 0 AN: 44668

Ashkenazi Jewish (ASJ) AF: 0.00173 AC: 45 AN: 26070

East Asian (EAS) AF: 0.00960 AC: 381 AN: 39670

South Asian (SAS) AF: 0.000348 AC: 30 AN: 86160

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5754

European-Non Finnish (NFE) AF: 0.00000723 AC: 8 AN: 1107122

Other (OTH) AF: 0.000814 AC: 49 AN: 60168

GnomAD4 genome AF: 0.000539 AC: 82 AN: 152092 Hom.: 0 Cov.: 32 AF XY: 0.000646 AC XY: 48 AN XY: 74354

African (AFR) AF: 0.00 AC: 0 AN: 41510

American (AMR) AF: 0.00 AC: 0 AN: 15260

Ashkenazi Jewish (ASJ) AF: 0.00260 AC: 9 AN: 3468

East Asian (EAS) AF: 0.0122 AC: 63 AN: 5154

South Asian (SAS) AF: 0.00166 AC: 8 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10592

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67972

Other (OTH) AF: 0.000473 AC: 1 AN: 2114

Alfa AF: 0.000483 Hom.: 3

Bravo AF: 0.000616

ExAC AF: 0.000939 AC: 114

Asia WGS AF: 0.00520 AC: 18 AN: 3478

EpiCase AF: 0.000109

EpiControl AF: 0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Merosin deficient congenital muscular dystrophy Uncertain:1

Jan 17, 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.

not provided Uncertain:1

Apr 03, 2019

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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.

not specified Benign:1

Oct 19, 2015

Genetic Services Laboratory, University of Chicago

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

LAMA2-related muscular dystrophy Benign:1

Jan 06, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Jun 22, 2018

Knight Diagnostic Laboratories, Oregon Health and Sciences University

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.85
BayesDel_addAF	Benign	-0.29	T
BayesDel_noAF	Benign	-0.17
CADD	Pathogenic	31
DANN	Uncertain	0.99
DEOGEN2	Benign	0.011	T
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Uncertain	0.93	D
MetaRNN	Benign	0.012	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.6	L
PhyloP100		2.3
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-1.1	N
REVEL	Benign	0.12
Sift	Uncertain	0.020	D
Polyphen		1.0	D
Vest4		0.77
MutPred		0.65		Loss of catalytic residue at W739 (P = 0.0034)
MVP		0.62
MPC		0.56
ClinPred		0.043	T
GERP RS		5.7
Varity_R		0.18
gMVP		0.76
Mutation Taster		=75/25	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.14		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs192317605; hg19: chr6-129588259; COSMIC: COSV70346672;