chr3-49122930-T-G

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 2P and 7B. PM2BP4_StrongBP6_ModerateBP7

The NM_002292.4(LAMB2):ā€‹c.4347A>Cā€‹(p.Ala1449=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000273 in 1,608,908 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 Likely benign (ā˜…).

Frequency

Genomes: š‘“ 0.000013 ( 0 hom., cov: 33)
Exomes š‘“: 0.000029 ( 0 hom. )

Consequence

LAMB2
NM_002292.4 synonymous

Scores

2

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: -1.24
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.53).
BP6
Variant 3-49122930-T-G is Benign according to our data. Variant chr3-49122930-T-G is described in ClinVar as [Likely_benign]. Clinvar id is 539739.Status of the report is criteria_provided_single_submitter, 1 stars.
BP7
Synonymous conserved (PhyloP=-1.24 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
LAMB2NM_002292.4 linkuse as main transcriptc.4347A>C p.Ala1449= synonymous_variant 27/32 ENST00000305544.9 NP_002283.3
LAMB2XM_005265127.5 linkuse as main transcriptc.4347A>C p.Ala1449= synonymous_variant 28/33 XP_005265184.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
LAMB2ENST00000305544.9 linkuse as main transcriptc.4347A>C p.Ala1449= synonymous_variant 27/321 NM_002292.4 ENSP00000307156 P1
LAMB2ENST00000418109.5 linkuse as main transcriptc.4347A>C p.Ala1449= synonymous_variant 28/331 ENSP00000388325 P1
LAMB2ENST00000469665.1 linkuse as main transcriptn.656A>C non_coding_transcript_exon_variant 3/32

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152162
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000203
AC:
5
AN:
246062
Hom.:
0
AF XY:
0.0000299
AC XY:
4
AN XY:
133704
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000178
Gnomad OTH exome
AF:
0.000164
GnomAD4 exome
AF:
0.0000288
AC:
42
AN:
1456628
Hom.:
0
Cov.:
34
AF XY:
0.0000290
AC XY:
21
AN XY:
724876
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.000112
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000279
Gnomad4 OTH exome
AF:
0.0000663
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152280
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74458
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.000131
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000283
Hom.:
0
Bravo
AF:
0.0000113
EpiCase
AF:
0.000218
EpiControl
AF:
0.00

ClinVar

Significance: Likely benign
Submissions summary: Benign:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Pierson syndrome;C3280113:LAMB2-related infantile-onset nephrotic syndrome Benign:1
Likely benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpOct 30, 2023- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.53
CADD
Benign
1.9
DANN
Benign
0.74

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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.

Other links and lift over

dbSNP: rs202083663; hg19: chr3-49160363; API