rs758825199

Variant names:

• chr3-49132591-G-A
• rs758825199
• NM_002292.4:c.149C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_002292.4(LAMB2):​c.149C>T​(p.Ala50Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000266 in 1,613,644 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000029 (0 hom.)
• Consequence: LAMB2 NM_002292.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.42
• 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: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

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.149C>T	p.Ala50Val	missense	Exon 2 of 32	NP_002283.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMB2	ENST00000305544.9	TSL:1 MANE Select	c.149C>T	p.Ala50Val	missense	Exon 2 of 32	ENSP00000307156.4	P55268
	LAMB2	ENST00000418109.5	TSL:1	c.149C>T	p.Ala50Val	missense	Exon 3 of 33	ENSP00000388325.1	P55268
	LAMB2	ENST00000960189.1		c.149C>T	p.Ala50Val	missense	Exon 2 of 32	ENSP00000630248.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152258 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000280 AC: 7 AN: 250102 AF XY: 0.0000148

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000619

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000287 AC: 42 AN: 1461386 Hom.: 0 Cov.: 32 AF XY: 0.0000248 AC XY: 18 AN XY: 727030

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52952

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000378 AC: 42 AN: 1111994

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152258 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74386

African (AFR) AF: 0.00 AC: 0 AN: 41466

American (AMR) AF: 0.00 AC: 0 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68044

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000564 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	2	-	Pierson syndrome;C3280113:LAMB2-related infantile-onset nephrotic syndrome (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Benign	-0.048	T
BayesDel_noAF	Benign	-0.15
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.50	T
Eigen	Pathogenic	0.70
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Uncertain	0.80	D
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.064	D
MetaRNN	Uncertain	0.55	D
MetaSVM	Uncertain	0.21	D
MutationAssessor	Uncertain	2.3	M
PhyloP100		5.4
PrimateAI	Uncertain	0.75	T
PROVEAN	Uncertain	-3.6	D
REVEL	Uncertain	0.63
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0040	D
Polyphen		0.96	D
Vest4		0.38
MutPred		0.73		Loss of disorder (P = 0.0867)
MVP		0.87
MPC		0.95
ClinPred		0.97	D
GERP RS		4.9
PromoterAI		0.045	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6
Varity_R		0.63
gMVP		0.69
Mutation Taster		=65/35	polymorphism

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

Other links and lift over

dbSNP: rs758825199; hg19: chr3-49170024;