Variant chr3-49121389-G-C details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_002292.4(LAMB2):c.5261-27C>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000725 in 1,614,100 control chromosomes in the GnomAD database, including 11 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0040 ( 6 hom., cov: 33)

Exomes 𝑓: 0.00038 ( 5 hom. )

Consequence

LAMB2
NM_002292.4 intron

Scores

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:2

Conservation

PhyloP100: 0.580

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:

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -20 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.88).

BP6

Variant 3-49121389-G-C is Benign according to our data. Variant chr3-49121389-G-C is described in ClinVar as [Likely_benign]. Clinvar id is 1199749.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00405 (616/152268) while in subpopulation AFR AF= 0.0143 (592/41536). AF 95% confidence interval is 0.0133. There are 6 homozygotes in gnomad4. There are 294 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 6 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMB2	NM_002292.4 linkuse as main transcript	c.5261-27C>G		intron_variant		ENST00000305544.9
LAMB2	XM_005265127.5 linkuse as main transcript	c.5261-27C>G		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMB2	ENST00000305544.9 linkuse as main transcript	c.5261-27C>G		intron_variant		1	NM_002292.4	P1

Frequencies

GnomAD3 genomes

AF:

0.00403

AC:

613

AN:

152150

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0142

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00111

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00191

GnomAD3 exomes

AF:

0.00101

AC:

253

AN:

251424

Hom.:

AF XY:

0.000846

AC XY:

115

AN XY:

135908

show subpopulations

Gnomad AFR exome

AF:

0.0134

Gnomad AMR exome

AF:

0.000809

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:

0.0000440

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000380

AC:

555

AN:

1461832

Hom.:

Cov.:

AF XY:

0.000367

AC XY:

267

AN XY:

727222

show subpopulations

Gnomad4 AFR exome

AF:

0.0126

Gnomad4 AMR exome

AF:

0.00101

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000243

Gnomad4 OTH exome

AF:

0.000861

GnomAD4 genome

AF:

0.00405

AC:

616

AN:

152268

Hom.:

Cov.:

AF XY:

0.00395

AC XY:

294

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.0143

Gnomad4 AMR

AF:

0.00111

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:

0.00189

Alfa

AF:

0.00244

Hom.:

Bravo

AF:

0.00457

Asia WGS

AF:

0.000866

AC:

AN:

3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:2

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 02, 2020	- -
Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.88

CADD

Benign

1.6

DANN

Benign

0.28

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