rs143405268

Positions:

chr3-49126040-G-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The ENST00000305544.9(LAMB2):c.2271C>A(p.Ser757Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00023 in 1,614,182 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S757N) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00024 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00023 ( 1 hom. )

Consequence

LAMB2
ENST00000305544.9 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 0.403

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]

LAMB2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.030513823).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LAMB2	NM_002292.4 linkuse as main transcript	c.2271C>A	p.Ser757Arg	missense_variant	17/32	ENST00000305544.9	NP_002283.3
LAMB2	XM_005265127.5 linkuse as main transcript	c.2271C>A	p.Ser757Arg	missense_variant	18/33		XP_005265184.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LAMB2	ENST00000305544.9 linkuse as main transcript	c.2271C>A	p.Ser757Arg	missense_variant	17/32	1	NM_002292.4	ENSP00000307156	P1

Frequencies

GnomAD3 genomes

AF:

0.000237

AC:

AN:

152198

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00173

Gnomad SAS

AF:

0.000828

Gnomad FIN

AF:

0.000377

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000265

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000398

AC:

100

AN:

251248

Hom.:

AF XY:

0.000398

AC XY:

AN XY:

135830

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000870

Gnomad SAS exome

AF:

0.000523

Gnomad FIN exome

AF:

0.000601

Gnomad NFE exome

AF:

0.000475

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000230

AC:

336

AN:

1461866

Hom.:

Cov.:

AF XY:

0.000235

AC XY:

171

AN XY:

727234

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00106

Gnomad4 SAS exome

AF:

0.000556

Gnomad4 FIN exome

AF:

0.000693

Gnomad4 NFE exome

AF:

0.000174

Gnomad4 OTH exome

AF:

0.000232

GnomAD4 genome

AF:

0.000236

AC:

AN:

152316

Hom.:

Cov.:

AF XY:

0.000322

AC XY:

AN XY:

74480

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000653

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00174

Gnomad4 SAS

AF:

0.000829

Gnomad4 FIN

AF:

0.000377

Gnomad4 NFE

AF:

0.000265

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000204

Hom.:

Bravo

AF:

0.000185

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.000428

AC:

Asia WGS

AF:

0.00202

AC:

AN:

3478

EpiCase

AF:

0.000273

EpiControl

AF:

0.000296

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Pierson syndrome;C3280113:LAMB2-related infantile-onset nephrotic syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 21, 2023	This sequence change replaces serine, which is neutral and polar, with arginine, which is basic and polar, at codon 757 of the LAMB2 protein (p.Ser757Arg). This variant is present in population databases (rs143405268, gnomAD 0.1%). 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: 576812). 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 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Mar 12, 2022	- -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 06, 2023

The c.2271C>A (p.S757R) alteration is located in exon 17 (coding exon 17) of the LAMB2 gene. This alteration results from a C to A substitution at nucleotide position 2271, causing the serine (S) at amino acid position 757 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Oct 01, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.26

BayesDel_addAF

Benign

-0.48

BayesDel_noAF

Benign

-0.52

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.16

T;T

Eigen

Benign

-0.44

Eigen_PC

Benign

-0.34

FATHMM_MKL

Uncertain

0.77

LIST_S2

Benign

0.63

.;T

M_CAP

Benign

0.017

MetaRNN

Benign

0.031

T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.9

L;L

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.56

PROVEAN

Benign

-1.4

N;N

REVEL

Benign

0.040

Sift

Uncertain

0.025

D;D

Sift4G

Benign

0.070

T;T

Polyphen

0.47

P;P

Vest4

0.20

MutPred

0.38

Loss of glycosylation at S757 (P = 0.0159);Loss of glycosylation at S757 (P = 0.0159);

MVP

0.26

MPC

0.18

ClinPred

0.024

GERP RS

3.9

Varity_R

0.062

gMVP

0.62

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over