NM_001105206.3:c.1961C>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP3BS2

The NM_001105206.3(LAMA4):​c.1961C>T​(p.Ala654Val) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000231 in 1,598,888 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. A654A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

LAMA4
NM_001105206.3 missense, splice_region

Scores

1
7
10
Splicing: ADA: 0.9774
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 6.83

Publications

0 publications found
Variant links:
Genes affected
LAMA4 (HGNC:6484): (laminin subunit alpha 4) Laminins, a family of extracellular matrix glycoproteins, are the major noncollagenous constituent of basement membranes. They have been implicated in a wide variety of biological processes including cell adhesion, differentiation, migration, signaling, neurite outgrowth and metastasis. Laminins are composed of 3 non identical chains: laminin alpha, beta and gamma (formerly A, B1, and B2, respectively) and they form a cruciform structure consisting of 3 short arms, each formed by a different chain, and a long arm composed of all 3 chains. Each laminin chain is a multidomain protein encoded by a distinct gene. Several isoforms of each chain have been described. Different alpha, beta and gamma chain isomers combine to give rise to different heterotrimeric laminin isoforms which are designated by Arabic numerals in the order of their discovery, i.e. alpha1beta1gamma1 heterotrimer is laminin 1. The biological functions of the different chains and trimer molecules are largely unknown, but some of the chains have been shown to differ with respect to their tissue distribution, presumably reflecting diverse functions in vivo. This gene encodes the alpha chain isoform laminin, alpha 4. The domain structure of alpha 4 is similar to that of alpha 3, both of which resemble truncated versions of alpha 1 and alpha 2, in that approximately 1,200 residues at the N-terminus (domains IV, V and VI) have been lost. Laminin, alpha 4 contains the C-terminal G domain which distinguishes all alpha chains from the beta and gamma chains. The RNA analysis from adult and fetal tissues revealed developmental regulation of expression, however, the exact function of laminin, alpha 4 is not known. Tissue-specific utilization of alternative polyA-signal has been described in literature. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Aug 2011]
LAMA4 Gene-Disease associations (from GenCC):
  • dilated cardiomyopathy 1JJ
    Inheritance: AD Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Illumina
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • dilated cardiomyopathy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
BS2
High AC in GnomAdExome4 at 34 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMA4NM_001105206.3 linkc.1961C>T p.Ala654Val missense_variant, splice_region_variant Exon 16 of 39 ENST00000230538.12 NP_001098676.2 Q16363A0A0A0MQS9

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMA4ENST00000230538.12 linkc.1961C>T p.Ala654Val missense_variant, splice_region_variant Exon 16 of 39 1 NM_001105206.3 ENSP00000230538.7 A0A0A0MQS9

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152096
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
250794
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000235
AC:
34
AN:
1446792
Hom.:
0
Cov.:
27
AF XY:
0.0000264
AC XY:
19
AN XY:
720882
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33198
American (AMR)
AF:
0.0000448
AC:
2
AN:
44692
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25998
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39612
South Asian (SAS)
AF:
0.0000233
AC:
2
AN:
85934
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52992
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.0000273
AC:
30
AN:
1098722
Other (OTH)
AF:
0.00
AC:
0
AN:
59890
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.454
Heterozygous variant carriers
0
3
5
8
10
13
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152096
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74292
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41416
American (AMR)
AF:
0.000131
AC:
2
AN:
15248
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2082
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.442
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Dilated cardiomyopathy 1JJ Uncertain:1
Oct 13, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 647 of the LAMA4 protein (p.Ala647Val). This variant is present in population databases (rs782806847, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with LAMA4-related conditions. ClinVar contains an entry for this variant (Variation ID: 541217). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

not provided Uncertain:1
Oct 24, 2017
Stanford Center for Inherited Cardiovascular Disease, Stanford University
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:provider interpretation

Found on postmortem testing of a 17-year-old with a negative autopsy and a history of 2 seizures in one day and then a sudden death a few months later. A 148-gene Arrhythmia and Cardiomyopathy Comprehensive Panel was done by the Invitae laboratory. This included Sudden Death in Epilepsy genes. Results included 3 variants: -p.Thr368Ile (c.1103C>T) in the DSC2 gene -p.Ala647Val (c.1940C>T) in the LAMA4 gene -p.Arg177Cys (c.529C>T) in the MYBPC3 gene p.Ala647Val (c.1940C>T) in exon 16 of the LAMA4 gene (NM_002290.4; ENST00000522006.5) Chromosome location 6:112476148 G / A Based on the information reviewed below, we classify it as a Variant of Uncertain Significance, concluding that there is not sufficient evidence for its pathogenicity to warrant using it for diagnosis or predictive genetic testing. The LAMA4 gene currently has no well-established disease association; there is preliminary evidence supporting a correlation with autosomal dominant dilated cardiomyopathy (DCM). The Ala647Val variant has not been published in association with disease. This is a conservative amino acid change, resulting in the replacement of a nonpolar Alanine with a nonpolar Valine. Alanine at this location is absolutely conserved across ~100 vertebrate species for which we have data. This codon is directly adjacent to an intron, which might raise questions of splicing. There are no Likely Pathogenic or Pathogenic variants listed in ClinVar within 10 amino acids to either side, indicating that this region of the protein might be tolerant of change. According to the Invitae report, 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 disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant was reported in 6 individuals in the gnomAD database, which includes variant calls on ~140,000 individuals of European, African, Latino, South Asian, Ashkenazi, and East Asian descent. Specifically, the variant was observed in 2 people with Latino ancestry (for the highest allele frequency: 0.006%), 1 East Asian, 1 South Asian, and 2 non-Finnish Europeans. Overall MAF 0.002%. The phenotype of those individuals is not publicly available. The dataset is comprised of multiple cohorts, some of which were recruited from the general population, others were enriched for common cardiovascular disease. The curators made an effort to exclude individuals with severe pediatric diseases. -

Cardiovascular phenotype Uncertain:1
Apr 16, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A647V variant (also known as c.1940C>T), located in coding exon 15 of the LAMA4 gene, results from a C to T substitution at nucleotide position 1940. The alanine at codon 647 is replaced by valine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. The evidence for this gene-disease relationship is limited; therefore, the clinical significance of this alteration is unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.29
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Benign
-0.23
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Benign
0.015
T;T;T;T
Eigen
Uncertain
0.44
Eigen_PC
Uncertain
0.49
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.86
D;.;.;D
M_CAP
Benign
0.012
T
MetaRNN
Uncertain
0.45
T;T;T;T
MetaSVM
Benign
-1.1
T
PhyloP100
6.8
PrimateAI
Uncertain
0.59
T
PROVEAN
Benign
-0.75
N;N;N;N
REVEL
Benign
0.13
Sift
Benign
0.065
T;T;T;T
Sift4G
Uncertain
0.0090
D;D;D;D
Vest4
0.78
MutPred
0.39
Gain of catalytic residue at D649 (P = 0.2422);.;.;.;
MVP
0.30
MPC
0.43
ClinPred
0.81
D
GERP RS
5.2
gMVP
0.34
Mutation Taster
=60/40
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
0.98
dbscSNV1_RF
Pathogenic
0.84
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: rs782806847; hg19: chr6-112476148; COSMIC: COSV57892232; COSMIC: COSV57892232; API