rs752674803

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_002292.4(LAMB2):​c.4877G>C​(p.Arg1626Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

LAMB2
NM_002292.4 missense

Scores

4
15

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.722
Variant links:
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

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=0.18559673).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMB2NM_002292.4 linkc.4877G>C p.Arg1626Pro missense_variant Exon 29 of 32 ENST00000305544.9 NP_002283.3 P55268
LAMB2XM_005265127.5 linkc.4877G>C p.Arg1626Pro missense_variant Exon 30 of 33 XP_005265184.1 P55268

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMB2ENST00000305544.9 linkc.4877G>C p.Arg1626Pro missense_variant Exon 29 of 32 1 NM_002292.4 ENSP00000307156.4 P55268
LAMB2ENST00000418109.5 linkc.4877G>C p.Arg1626Pro missense_variant Exon 30 of 33 1 ENSP00000388325.1 P55268
LAMB2ENST00000498377.1 linkn.532G>C non_coding_transcript_exon_variant Exon 2 of 5 2
LAMB2ENST00000467506.5 linkn.-14G>C upstream_gene_variant 2

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461608
Hom.:
0
Cov.:
33
AF XY:
0.00000413
AC XY:
3
AN XY:
727138
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
33
Bravo
AF:
0.00000378

ClinVar

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

Submissions by phenotype

Pierson syndrome;C3280113:LAMB2-related infantile-onset nephrotic syndrome Uncertain:1
Mar 09, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 1626 of the LAMB2 protein (p.Arg1626Pro). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with LAMB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 472490). 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. 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
Uncertain
0.39
BayesDel_addAF
Benign
-0.16
T
BayesDel_noAF
Benign
-0.47
CADD
Benign
15
DANN
Uncertain
0.98
DEOGEN2
Benign
0.34
T;T
Eigen
Benign
-0.59
Eigen_PC
Benign
-0.64
FATHMM_MKL
Benign
0.13
N
LIST_S2
Benign
0.56
.;T
M_CAP
Benign
0.027
D
MetaRNN
Benign
0.19
T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
1.5
L;L
PrimateAI
Benign
0.21
T
PROVEAN
Uncertain
-2.8
D;D
REVEL
Benign
0.098
Sift
Uncertain
0.026
D;D
Sift4G
Benign
0.14
T;T
Polyphen
0.64
P;P
Vest4
0.42
MutPred
0.34
Loss of MoRF binding (P = 2e-04);Loss of MoRF binding (P = 2e-04);
MVP
0.27
MPC
0.31
ClinPred
0.62
D
GERP RS
-2.4
Varity_R
0.37
gMVP
0.65

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs752674803; hg19: chr3-49159423; COSMIC: COSV59731108; COSMIC: COSV59731108; API