6-112122034-T-G

Variant names:

• chr6-112122034-T-G
• rs1554326282
• NM_001105206.3:c.4455A>C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001105206.3(LAMA4):​c.4455A>C​(p.Leu1485Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/19 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)
• Consequence: LAMA4 NM_001105206.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.104

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.18764901).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMA4	NM_001105206.3	c.4455A>C	p.Leu1485Phe	missense_variant	Exon 32 of 39	ENST00000230538.12	NP_001098676.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA4	ENST00000230538.12	c.4455A>C	p.Leu1485Phe	missense_variant	Exon 32 of 39	1	NM_001105206.3	ENSP00000230538.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Oct 25, 2016

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Leu1478Phe variant in LAMA4 has not been previously reported in individual s with cardiomyopathy and was absent from large population studies. Computationa l prediction tools and conservation analysis suggest that the p.Leu1478Phe varia nt may not impact the protein, though this information is not predictive enough to rule out pathogenicity. In summary, the clinical significance of the p.Leu147 8Phe variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.088
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.60
CADD	Benign	18
DANN	Uncertain	0.99
DEOGEN2	Benign	0.030	T;T;T;T
Eigen	Benign	-0.40
Eigen_PC	Benign	-0.46
FATHMM_MKL	Benign	0.65	D
LIST_S2	Benign	0.67	T;.;.;T
M_CAP	Benign	0.0080	T
MetaRNN	Benign	0.19	T;T;T;T
MetaSVM	Benign	-1.0	T
PrimateAI	Benign	0.47	T
PROVEAN	Benign	-1.7	N;N;N;N
REVEL	Benign	0.13
Sift	Benign	0.11	T;T;T;T
Sift4G	Uncertain	0.053	T;T;T;T
Vest4		0.12
MutPred		0.70		Gain of methylation at K1486 (P = 0.0371);.;.;.;
MVP		0.38
MPC		0.13
ClinPred		0.18	T
GERP RS		-4.4
gMVP		0.35

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs1554326282; hg19: chr6-112443237;