3-49121244-G-C

Variant summary

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

The NM_002292.4(LAMB2):c.5379C>G(p.Ile1793Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000213 in 1,612,160 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. I1793I) has been classified as Benign.

Frequency

Genomes: 𝑓 0.00018 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00022 ( 0 hom. )

Consequence

LAMB2
NM_002292.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 1.93

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=0.16025978).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMB2	NM_002292.4 linkuse as main transcript	c.5379C>G	p.Ile1793Met	missense_variant	32/32	ENST00000305544.9
LAMB2	XM_005265127.5 linkuse as main transcript	c.5379C>G	p.Ile1793Met	missense_variant	33/33

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMB2	ENST00000305544.9 linkuse as main transcript	c.5379C>G	p.Ile1793Met	missense_variant	32/32	1	NM_002292.4	P1

Frequencies

GnomAD3 genomes

AF:

0.000184

AC:

AN:

152228

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000458

Gnomad ASJ

AF:

0.00173

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000191

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000135

AC:

AN:

251198

Hom.:

AF XY:

0.000147

AC XY:

AN XY:

135832

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.000497

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000925

Gnomad NFE exome

AF:

0.000203

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000216

AC:

316

AN:

1459932

Hom.:

Cov.:

AF XY:

0.000191

AC XY:

139

AN XY:

726264

show subpopulations

Gnomad4 AFR exome

AF:

0.0000599

Gnomad4 AMR exome

AF:

0.0000894

Gnomad4 ASJ exome

AF:

0.000344

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000937

Gnomad4 NFE exome

AF:

0.000255

Gnomad4 OTH exome

AF:

0.000183

GnomAD4 genome

AF:

0.000184

AC:

AN:

152228

Hom.:

Cov.:

AF XY:

0.000202

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.000458

Gnomad4 ASJ

AF:

0.00173

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000941

Gnomad4 NFE

AF:

0.000191

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000220

Hom.:

Bravo

AF:

0.000128

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.000107

AC:

EpiCase

AF:

0.000491

EpiControl

AF:

0.000415

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

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	Oct 24, 2022	This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 1793 of the LAMB2 protein (p.Ile1793Met). This variant is present in population databases (rs11550620, gnomAD 0.05%). 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: 444602). 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: "Probably Damaging"; Align-GVGD: "Class C0"). 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 30, 2022	- -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 08, 2022

The c.5379C>G (p.I1793M) alteration is located in exon 32 (coding exon 32) of the LAMB2 gene. This alteration results from a C to G substitution at nucleotide position 5379, causing the isoleucine (I) at amino acid position 1793 to be replaced by a methionine (M). 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

Jun 01, 2017

- -

LAMB2-related infantile-onset nephrotic syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Dec 18, 2018

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.36

BayesDel_addAF

Benign

-0.25

BayesDel_noAF

Benign

-0.31

Cadd

Benign

Dann

Uncertain

1.0

DEOGEN2

Benign

0.11

T;T

Eigen

Uncertain

0.44

Eigen_PC

Uncertain

0.39

FATHMM_MKL

Uncertain

0.90

M_CAP

Benign

0.024

MetaRNN

Benign

0.16

T;T

MetaSVM

Benign

-0.92

MutationAssessor

Uncertain

2.3

M;M

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.78

PROVEAN

Benign

-1.4

N;N

REVEL

Benign

0.16

Sift

Benign

0.059

T;T

Sift4G

Benign

0.20

T;T

Polyphen

1.0

D;D

Vest4

0.43

MVP

0.33

MPC

1.8

ClinPred

0.19

GERP RS

3.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.30

gMVP

0.26

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