rs1554305958

Variant names:

• chr6-129481431-A-T
• rs1554305958
• NM_000426.4:c.7741A>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000426.4(LAMA2):​c.7741A>T​(p.Thr2581Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,460,954 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: LAMA2 NM_000426.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.50
• Publications: 0 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)

LOC124901401 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17676225).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMA2	NM_000426.4	c.7741A>T	p.Thr2581Ser	missense_variant	Exon 55 of 65	ENST00000421865.3	NP_000417.3
LAMA2	NM_001079823.2	c.7729A>T	p.Thr2577Ser	missense_variant	Exon 54 of 64		NP_001073291.2
LOC124901401	XR_007059767.1	n.4952T>A		non_coding_transcript_exon_variant	Exon 2 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA2	ENST00000421865.3	c.7741A>T	p.Thr2581Ser	missense_variant	Exon 55 of 65	5	NM_000426.4	ENSP00000400365.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460954 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726848

African (AFR) AF: 0.00 AC: 0 AN: 33444

American (AMR) AF: 0.0000224 AC: 1 AN: 44700

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86240

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111236

Other (OTH) AF: 0.00 AC: 0 AN: 60366

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

LAMA2-related muscular dystrophy Uncertain:1

Aug 31, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine with serine at codon 2581 of the LAMA2 protein (p.Thr2581Ser). The threonine residue is moderately conserved and there is a small physicochemical difference between threonine and serine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with LAMA2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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	0.14
BayesDel_addAF	Benign	-0.26	T
BayesDel_noAF	Benign	-0.62
CADD	Benign	19
DANN	Uncertain	0.98
DEOGEN2	Benign	0.011	.;T;T
Eigen	Benign	0.0017
Eigen_PC	Benign	0.12
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.72	T;T;T
M_CAP	Benign	0.013	T
MetaRNN	Benign	0.18	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.1	.;.;L
PhyloP100		4.5
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-0.66	.;.;N
REVEL	Benign	0.057
Sift	Benign	0.21	.;.;T
Polyphen		0.34	.;.;B
Vest4		0.23
MutPred		0.40		.;.;Gain of glycosylation at T2581 (P = 0.0108);
MVP		0.53
MPC		0.20
ClinPred		0.76	D
GERP RS		4.2
Varity_R		0.063
gMVP		0.31
Mutation Taster		=95/5	polymorphism

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

Other links and lift over

dbSNP: rs1554305958; hg19: chr6-129802576;