rs148069401

Variant summary

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

The NM_002292.4(LAMB2):c.4559A>G(p.Lys1520Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000216 in 1,613,932 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00023 ( 0 hom. )

Consequence

LAMB2
NM_002292.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 2.99

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.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.082295924).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMB2	NM_002292.4 linkuse as main transcript	c.4559A>G	p.Lys1520Arg	missense_variant	27/32	ENST00000305544.9
LAMB2	XM_005265127.5 linkuse as main transcript	c.4559A>G	p.Lys1520Arg	missense_variant	28/33

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
LAMB2	ENST00000305544.9 linkuse as main transcript	c.4559A>G	p.Lys1520Arg	missense_variant	27/32	1	NM_002292.4	P1
LAMB2	ENST00000418109.5 linkuse as main transcript	c.4559A>G	p.Lys1520Arg	missense_variant	28/33	1		P1
LAMB2	ENST00000469665.1 linkuse as main transcript	n.868A>G		non_coding_transcript_exon_variant	3/3	2

Frequencies

GnomAD3 genomes

AF:

0.000118

AC:

AN:

152168

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000206

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000127

AC:

AN:

251470

Hom.:

AF XY:

0.000140

AC XY:

AN XY:

135910

show subpopulations

Gnomad AFR exome

AF:

0.000185

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000246

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000226

AC:

331

AN:

1461764

Hom.:

Cov.:

AF XY:

0.000210

AC XY:

153

AN XY:

727204

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000293

Gnomad4 OTH exome

AF:

0.0000662

GnomAD4 genome

AF:

0.000118

AC:

AN:

152168

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74334

show subpopulations

Gnomad4 AFR

AF:

0.0000965

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000206

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000177

Hom.:

Bravo

AF:

0.000110

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000906

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000296

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

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	Invitae	Aug 06, 2022	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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C25"). ClinVar contains an entry for this variant (Variation ID: 472486). This variant has not been reported in the literature in individuals affected with LAMB2-related conditions. This variant is present in population databases (rs148069401, gnomAD 0.02%). This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 1520 of the LAMB2 protein (p.Lys1520Arg). -
Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Mar 02, 2022	- -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 11, 2022

The c.4559A>G (p.K1520R) alteration is located in exon 27 (coding exon 27) of the LAMB2 gene. This alteration results from a A to G substitution at nucleotide position 4559, causing the lysine (K) at amino acid position 1520 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.093

BayesDel_addAF

Benign

-0.46

BayesDel_noAF

Benign

-0.60

Cadd

Benign

Dann

Benign

0.88

DEOGEN2

Benign

0.053

T;T

Eigen

Benign

-0.28

Eigen_PC

Benign

-0.029

FATHMM_MKL

Uncertain

0.83

M_CAP

Benign

0.0043

MetaRNN

Benign

0.082

T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

0.57

N;N

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.53

PROVEAN

Benign

0.040

N;N

REVEL

Benign

0.062

Sift

Benign

1.0

T;T

Sift4G

Benign

1.0

T;T

Polyphen

0.060

B;B

Vest4

0.16

MVP

0.40

MPC

0.15

ClinPred

0.049

GERP RS

5.6

Varity_R

0.068

gMVP

0.23

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.47

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.47

Position offset: 5

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