rs769399002

chr3-49122062-TG-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate

The NM_002292.4(LAMB2):c.4804del(p.Gln1602ArgfsTer52) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,613,468 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

LAMB2
NM_002292.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, single submitter P:2

Conservation

PhyloP100: 1.94

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 Pathogenic. Variant got 12 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 3-49122062-TG-T is Pathogenic according to our data. Variant chr3-49122062-TG-T is described in ClinVar as [Pathogenic]. Clinvar id is 14538.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr3-49122062-TG-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMB2	NM_002292.4 linkuse as main transcript	c.4804del	p.Gln1602ArgfsTer52	frameshift_variant	29/32	ENST00000305544.9
LAMB2	XM_005265127.5 linkuse as main transcript	c.4804del	p.Gln1602ArgfsTer52	frameshift_variant	30/33

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
LAMB2	ENST00000305544.9 linkuse as main transcript	c.4804del	p.Gln1602ArgfsTer52	frameshift_variant	29/32	1	NM_002292.4	P1
LAMB2	ENST00000418109.5 linkuse as main transcript	c.4804del	p.Gln1602ArgfsTer52	frameshift_variant	30/33	1		P1
LAMB2	ENST00000498377.1 linkuse as main transcript	n.459del		non_coding_transcript_exon_variant	2/5	2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152214

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000797

AC:

AN:

251046

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135800

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000616

AC:

AN:

1461254

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

726982

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000809

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74372

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

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

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Apr 12, 2021

For these reasons, this variant has been classified as Pathogenic. This variant has been observed in individual(s) with congenital myasthenic syndrome (PMID: 19251977). ClinVar contains an entry for this variant (Variation ID: 14538). This variant is present in population databases (rs769399002, ExAC 0.002%). This sequence change creates a premature translational stop signal (p.Gln1602Argfs*52) in the LAMB2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in LAMB2 are known to be pathogenic (PMID: 15367484). -

LAMB2-related infantile-onset nephrotic syndrome

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Mar 01, 2009

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.080

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