3-49132371-C-T

Position:

chr3-49132371-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 4P and 4B. PM1PM2BP4_Strong

The NM_002292.4(LAMB2):c.284G>A(p.Arg95His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000057 in 1,614,206 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 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. R95P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00016 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000046 ( 0 hom. )

Consequence

LAMB2
NM_002292.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: -0.417

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 Uncertain_significance. Variant got 0 ACMG points.

PM1

In a domain Laminin N-terminal (size 239) in uniprot entity LAMB2_HUMAN there are 14 pathogenic changes around while only 2 benign (88%) in NM_002292.4

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.018902749).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMB2	NM_002292.4 linkuse as main transcript	c.284G>A	p.Arg95His	missense_variant	3/32	ENST00000305544.9
LAMB2	XM_005265127.5 linkuse as main transcript	c.284G>A	p.Arg95His	missense_variant	4/33

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
LAMB2	ENST00000305544.9 linkuse as main transcript	c.284G>A	p.Arg95His	missense_variant	3/32	1	NM_002292.4	P1
LAMB2	ENST00000418109.5 linkuse as main transcript	c.284G>A	p.Arg95His	missense_variant	4/33	1		P1
LAMB2	ENST00000494831.1 linkuse as main transcript	c.-27-217G>A		intron_variant		2

Frequencies

GnomAD3 genomes

AF:

0.000164

AC:

AN:

152200

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000338

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00135

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000139

AC:

AN:

251472

Hom.:

AF XY:

0.000118

AC XY:

AN XY:

135922

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00179

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000458

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.0000399

AC XY:

AN XY:

727244

show subpopulations

Gnomad4 AFR exome

AF:

0.000149

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00128

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.0000828

GnomAD4 genome

AF:

0.000164

AC:

AN:

152318

Hom.:

Cov.:

AF XY:

0.000175

AC XY:

AN XY:

74488

show subpopulations

Gnomad4 AFR

AF:

0.000337

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00135

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.000212

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.000140

AC:

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	Fulgent Genetics, Fulgent Genetics	Feb 02, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 15, 2022	This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 95 of the LAMB2 protein (p.Arg95His). This variant is present in population databases (rs147691227, gnomAD 0.2%). 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: 583002). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The histidine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

LAMB2-related infantile-onset nephrotic syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Mar 23, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Pierson syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Mar 23, 2018

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.069

BayesDel_addAF

Benign

-0.44

BayesDel_noAF

Benign

-0.41

CADD

Benign

DANN

Benign

0.97

DEOGEN2

Benign

0.18

T;T

Eigen

Benign

-0.78

Eigen_PC

Benign

-0.70

FATHMM_MKL

Benign

0.058

LIST_S2

Benign

0.16

.;T

M_CAP

Benign

0.017

MetaRNN

Benign

0.019

T;T

MetaSVM

Benign

-0.91

MutationAssessor

Benign

1.3

L;L

MutationTaster

Benign

1.0

D;D

PrimateAI

Benign

0.31

PROVEAN

Benign

0.10

N;N

REVEL

Benign

0.099

Sift

Benign

0.21

T;T

Sift4G

Benign

0.16

T;T

Polyphen

0.019

B;B

Vest4

0.32

MVP

0.46

MPC

0.59

ClinPred

0.024

GERP RS

1.4

Varity_R

0.027

gMVP

0.51

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.18

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