rs1209180229

chr6-112115954-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_001105206.3(LAMA4):c.5021T>G(p.Phe1674Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,461,106 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000019 (0 hom.)
• Consequence: LAMA4 NM_001105206.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.10

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]

LOC107986633 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.847

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMA4	NM_001105206.3	c.5021T>G	p.Phe1674Cys	missense_variant	36/39	ENST00000230538.12
LOC107986633	XR_001744299.2			upstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMA4	ENST00000230538.12	c.5021T>G	p.Phe1674Cys	missense_variant	36/39	1	NM_001105206.3	A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251136 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135710

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000192 AC: 28 AN: 1461106 Hom.: 0 Cov.: 30 AF XY: 0.0000234 AC XY: 17 AN XY: 726870

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000234

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Dilated cardiomyopathy 1JJ Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 27, 2023

This sequence change replaces phenylalanine, which is neutral and non-polar, with cysteine, which is neutral and slightly polar, at codon 1667 of the LAMA4 protein (p.Phe1667Cys). This variant is present in population databases (no rsID available, gnomAD no frequency). 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: 518525). 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. -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 25, 2016

The p.F1667C variant (also known as c.5000T>G), located in coding exon 35 of the LAMA4 gene, results from a T to G substitution at nucleotide position 5000. The phenylalanine at codon 1667 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6503 samples (13006 alleles) with coverage at this position. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.85
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.33
Cadd	Pathogenic	28
Dann	Uncertain	0.99
DEOGEN2	Benign	0.17	T;T;T;T
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.89	D;.;.;D
M_CAP	Uncertain	0.085	D
MetaRNN	Pathogenic	0.85	D;D;D;D
MetaSVM	Uncertain	0.28	D
MutationTaster	Benign	0.98	D;D;D;D
PrimateAI	Uncertain	0.65	T
PROVEAN	Uncertain	-4.2	D;D;D;D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0030	D;D;D;D
Sift4G	Uncertain	0.0030	D;D;D;D
Vest4		0.79
MVP		0.87
MPC		0.64
ClinPred		0.98	D
GERP RS		5.3
gMVP		0.80

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

LitVar

Other links and lift over

dbSNP: rs1209180229; hg19: chr6-112437157;