3-49121228-AC-A
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Variant summary
Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_ModeratePM2
The NM_002292.4(LAMB2):c.5394delG(p.Gln1798fs) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).
Frequency
Genomes: not found (cov: 33)
Consequence
LAMB2
NM_002292.4 frameshift
NM_002292.4 frameshift
Scores
Not classified
Clinical Significance
Conservation
PhyloP100: 3.96
Genes affected
LAMB2 (HGNC:6487): (laminin subunit beta 2) 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, composed of 3 non identical chains: laminin alpha, beta and gamma (formerly A, B1, and B2, respectively), 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 beta chain isoform laminin, beta 2. The beta 2 chain contains the 7 structural domains typical of beta chains of laminin, including the short alpha region. However, unlike beta 1 chain, beta 2 has a more restricted tissue distribution. It is enriched in the basement membrane of muscles at the neuromuscular junctions, kidney glomerulus and vascular smooth muscle. Transgenic mice in which the beta 2 chain gene was inactivated by homologous recombination, showed defects in the maturation of neuromuscular junctions and impairment of glomerular filtration. Alternative splicing involving a non consensus 5' splice site (gc) in the 5' UTR of this gene has been reported. It was suggested that inefficient splicing of this first intron, which does not change the protein sequence, results in a greater abundance of the unspliced form of the transcript than the spliced form. The full-length nature of the spliced transcript is not known. [provided by RefSeq, Aug 2011]
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ACMG classification
Classification made for transcript
Verdict is Uncertain_significance. Variant got 4 ACMG points.
PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.000556 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes
GnomAD3 genomes
Cov.:
33
GnomAD4 exome Cov.: 32
GnomAD4 exome
Cov.:
32
GnomAD4 genome
GnomAD4 genome
Cov.:
33
ClinVar
Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link
Submissions by phenotype
not provided Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Revvity Omics, Revvity | Jun 14, 2021 | - - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
Splicing
Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at
Publications
No publications associated with this variant yet.