rs527639885

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_002292.4(LAMB2):​c.2669C>T​(p.Thr890Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0004 in 1,613,952 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T890K) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00022 ( 1 hom., cov: 33)
Exomes 𝑓: 0.00042 ( 6 hom. )

Consequence

LAMB2
NM_002292.4 missense

Scores

5
8
5

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:3

Conservation

PhyloP100: 5.75

Publications

1 publications found
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 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)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -13 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.018673867).
BP6
Variant 3-49125304-G-A is Benign according to our data. Variant chr3-49125304-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 586112.
BS1
Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.000223 (34/152354) while in subpopulation SAS AF = 0.00662 (32/4832). AF 95% confidence interval is 0.00482. There are 1 homozygotes in GnomAd4. There are 28 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High Homozygotes in GnomAdExome4 at 6 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMB2NM_002292.4 linkc.2669C>T p.Thr890Ile missense_variant Exon 19 of 32 ENST00000305544.9 NP_002283.3 P55268
LAMB2XM_005265127.5 linkc.2669C>T p.Thr890Ile missense_variant Exon 20 of 33 XP_005265184.1 P55268

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMB2ENST00000305544.9 linkc.2669C>T p.Thr890Ile missense_variant Exon 19 of 32 1 NM_002292.4 ENSP00000307156.4 P55268

Frequencies

GnomAD3 genomes
AF:
0.000223
AC:
34
AN:
152236
Hom.:
1
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000482
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00662
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000764
AC:
192
AN:
251278
AF XY:
0.00104
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000352
Gnomad OTH exome
AF:
0.000978
GnomAD4 exome
AF:
0.000418
AC:
611
AN:
1461598
Hom.:
6
Cov.:
35
AF XY:
0.000602
AC XY:
438
AN XY:
727100
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.00655
AC:
565
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53124
Middle Eastern (MID)
AF:
0.000347
AC:
2
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000719
AC:
8
AN:
1112012
Other (OTH)
AF:
0.000580
AC:
35
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
Heterozygous variant carriers
0
53
105
158
210
263
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
10
20
30
40
50
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000223
AC:
34
AN:
152354
Hom.:
1
Cov.:
33
AF XY:
0.000376
AC XY:
28
AN XY:
74508
show subpopulations
African (AFR)
AF:
0.0000481
AC:
2
AN:
41580
American (AMR)
AF:
0.00
AC:
0
AN:
15308
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5180
South Asian (SAS)
AF:
0.00662
AC:
32
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.502
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000181
Hom.:
0
Bravo
AF:
0.0000378
ExAC
AF:
0.000881
AC:
107
Asia WGS
AF:
0.00289
AC:
10
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:1
Jul 19, 2023
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

BS1 -

Mar 08, 2018
Athena Diagnostics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 27, 2023
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported with a second variant (phase unknown) in a patient with minimal change disease and IgA nephropathy (Lata et al., 2018); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 29204651) -

Pierson syndrome;C3280113:LAMB2-related infantile-onset nephrotic syndrome Benign:1
Dec 04, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

LAMB2-related disorder Benign:1
Dec 29, 2021
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.46
BayesDel_addAF
Benign
-0.091
T
BayesDel_noAF
Uncertain
0.10
CADD
Uncertain
25
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.28
T;T
Eigen
Pathogenic
0.88
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.83
.;T
MetaRNN
Benign
0.019
T;T
MetaSVM
Uncertain
0.081
D
MutationAssessor
Pathogenic
3.9
H;H
PhyloP100
5.7
PrimateAI
Uncertain
0.56
T
PROVEAN
Pathogenic
-5.6
D;D
REVEL
Uncertain
0.48
Sift
Uncertain
0.0010
D;D
Sift4G
Uncertain
0.0020
D;D
Polyphen
1.0
D;D
Vest4
0.77
MutPred
0.67
Loss of disorder (P = 0.0319);Loss of disorder (P = 0.0319);
MVP
0.79
MPC
0.64
ClinPred
0.45
T
GERP RS
6.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.71
gMVP
0.59
Mutation Taster
=45/55
disease causing

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

Other links and lift over

dbSNP: rs527639885; hg19: chr3-49162737; API