rs201999373

Variant names:

• chr3-49130250-C-T
• rs201999373
• NM_002292.4:c.1206G>A

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_Strong BP6 BP7 BS2

The NM_002292.4(LAMB2):​c.1206G>A​(p.Arg402Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000836 in 1,614,242 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00014 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000077 (3 hom.)
• Consequence: LAMB2 NM_002292.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:3
• Conservation: PhyloP100: -0.368
• 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, STRONG, SUPPORTIVE Submitted by: G2P, PanelApp Australia, Orphanet
• LAMB2-related infantile-onset nephrotic syndrome

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

ACMG classification

Our verdict: Benign. The variant received -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.47).
• BP6: Variant 3-49130250-C-T is Benign according to our data. Variant chr3-49130250-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 258596.
• BP7: Synonymous conserved (PhyloP=-0.368 with no splicing effect.
• BS2: High Homozygotes in GnomAdExome4 at 3 AR gene

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.1206G>A	p.Arg402Arg	synonymous	Exon 9 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.1206G>A	p.Arg402Arg	synonymous	Exon 9 of 32	ENSP00000307156.4
	LAMB2	ENST00000418109.5	TSL:1	c.1206G>A	p.Arg402Arg	synonymous	Exon 10 of 33	ENSP00000388325.1
	LAMB2	ENST00000960189.1		c.1206G>A	p.Arg402Arg	synonymous	Exon 9 of 32	ENSP00000630248.1

Frequencies

GnomAD3 genomes AF: 0.000144 AC: 22 AN: 152266 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000964

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00308

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: 0.000306 AC: 77 AN: 251250 AF XY: 0.000236

Gnomad AFR exome AF: 0.000185

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00397

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000773 AC: 113 AN: 1461858 Hom.: 3 Cov.: 33 AF XY: 0.0000509 AC XY: 37 AN XY: 727238

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00214 AC: 85 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53388

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112012

Other (OTH) AF: 0.000431 AC: 26 AN: 60394

GnomAD4 genome AF: 0.000144 AC: 22 AN: 152384 Hom.: 0 Cov.: 33 AF XY: 0.000161 AC XY: 12 AN XY: 74520

African (AFR) AF: 0.0000962 AC: 4 AN: 41596

American (AMR) AF: 0.0000653 AC: 1 AN: 15310

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

East Asian (EAS) AF: 0.00309 AC: 16 AN: 5178

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10632

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68042

Other (OTH) AF: 0.00 AC: 0 AN: 2116

Alfa AF: 0.000107 Hom.: 0

Bravo AF: 0.000140

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

ClinVar submissions as Germline

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	-	2	not specified (2)
-	1	-	Kidney disorder (1)
-	1	-	LAMB2-related infantile-onset nephrotic syndrome (1)
-	1	-	Pierson syndrome (1)
-	-	1	Pierson syndrome;C3280113:LAMB2-related infantile-onset nephrotic syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.47
CADD	Benign	6.5
DANN	Benign	0.46
PhyloP100		-0.37
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=100/0	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: rs201999373; hg19: chr3-49167683;