rs990115860

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_000426.4(LAMA2):​c.6044C>T​(p.Thr2015Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000461 in 151,912 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 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. T2015P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Consequence

LAMA2
NM_000426.4 missense

Scores

2
1
15

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.29

Publications

2 publications found
Variant links:
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)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.032745898).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMA2NM_000426.4 linkc.6044C>T p.Thr2015Ile missense_variant Exon 42 of 65 ENST00000421865.3 NP_000417.3
LAMA2NM_001079823.2 linkc.6044C>T p.Thr2015Ile missense_variant Exon 42 of 64 NP_001073291.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMA2ENST00000421865.3 linkc.6044C>T p.Thr2015Ile missense_variant Exon 42 of 65 5 NM_000426.4 ENSP00000400365.2
LAMA2ENST00000618192.5 linkc.6308C>T p.Thr2103Ile missense_variant Exon 43 of 66 5 ENSP00000480802.2
LAMA2ENST00000617695.5 linkc.6044C>T p.Thr2015Ile missense_variant Exon 42 of 64 5 ENSP00000481744.2

Frequencies

GnomAD3 genomes
AF:
0.0000461
AC:
7
AN:
151912
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00658
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.:
27
GnomAD4 genome
AF:
0.0000461
AC:
7
AN:
151912
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74172
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41398
American (AMR)
AF:
0.00
AC:
0
AN:
15242
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10572
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67906
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000491

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

LAMA2-related muscular dystrophy Uncertain:1
Apr 23, 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 isoleucine at codon 2015 of the LAMA2 protein (p.Thr2015Ile). The threonine residue is weakly conserved and there is a moderate physicochemical difference between threonine and isoleucine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with LAMA2-related disease. 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, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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
0.11
BayesDel_addAF
Benign
-0.27
T
BayesDel_noAF
Benign
-0.63
CADD
Benign
21
DANN
Uncertain
0.99
DEOGEN2
Benign
0.0
.;T;T
Eigen
Benign
-0.36
Eigen_PC
Benign
-0.25
FATHMM_MKL
Benign
0.71
D
LIST_S2
Benign
0.61
T;T;T
M_CAP
Benign
0.0066
T
MetaRNN
Benign
0.033
T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.0
.;.;N
PhyloP100
1.3
PrimateAI
Benign
0.38
T
PROVEAN
Benign
0.0
.;.;N
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;.;T
Sift4G
Pathogenic
0.0
.;.;.
Vest4
0.22
ClinPred
0.23
T
GERP RS
3.6
Varity_R
0.12
gMVP
0.25
Mutation Taster
=99/1
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

Publications

Other links and lift over

dbSNP: rs990115860; hg19: chr6-129759866; API