rs1330915067

Variant names:

• chr3-49129153-C-A
• rs1330915067
• NM_002292.4:c.1599-1G>T

Your query was ambiguous. Multiple possible variants found:

• chr3-49129153-C-A
• chr3-49129153-C-T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_002292.4(LAMB2):​c.1599-1G>T variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: LAMB2 NM_002292.4 splice_acceptor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.93
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• Pierson syndrome

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
• LAMB2-related infantile-onset nephrotic syndrome

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-49129153-C-A is Pathogenic according to our data. Variant chr3-49129153-C-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 447697.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002292.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMB2	NM_002292.4	MANE Select	c.1599-1G>T		splice_acceptor intron	N/A	NP_002283.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMB2	ENST00000305544.9	TSL:1 MANE Select	c.1599-1G>T		splice_acceptor intron	N/A	ENSP00000307156.4	P55268
	LAMB2	ENST00000418109.5	TSL:1	c.1599-1G>T		splice_acceptor intron	N/A	ENSP00000388325.1	P55268
	LAMB2	ENST00000884814.1		c.1610G>T	p.Arg537Met	missense	Exon 13 of 32	ENSP00000554873.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
1	-	-	not provided (1)
1	-	-	Pierson syndrome;C3280113:LAMB2-related infantile-onset nephrotic syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	28
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		6.9
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
SpliceAI score (max)		0.93		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.20		Position offset: -18
DS_AL_spliceai		0.93		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1330915067; hg19: chr3-49166586;