rs146794392

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000228.3(LAMB3):​c.1978C>T​(p.Arg660*) variant causes a stop gained, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,612,492 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R660R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

LAMB3
NM_000228.3 stop_gained, splice_region

Scores

2
1
4
Splicing: ADA: 0.0004724
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: -0.00500

Publications

4 publications found
Variant links:
Genes affected
LAMB3 (HGNC:6490): (laminin subunit beta 3) The product encoded by this gene is a laminin that belongs to a family of basement membrane proteins. This protein is a beta subunit laminin, which together with an alpha and a gamma subunit, forms laminin-5. Mutations in this gene cause epidermolysis bullosa junctional Herlitz type, and generalized atrophic benign epidermolysis bullosa, diseases that are characterized by blistering of the skin. Multiple alternatively spliced transcript variants that encode the same protein have been found for this gene. [provided by RefSeq, Jul 2008]
LAMB3 Gene-Disease associations (from GenCC):
  • junctional epidermolysis bullosa
    Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
  • junctional epidermolysis bullosa Herlitz type
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet, Laboratory for Molecular Medicine
  • junctional epidermolysis bullosa, non-Herlitz type
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Genomics England PanelApp, Ambry Genetics
  • amelogenesis imperfecta type 1A
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • amelogenesis imperfecta type 1
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • generalized junctional epidermolysis bullosa non-Herlitz type
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 1-209623999-G-A is Pathogenic according to our data. Variant chr1-209623999-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 189034.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LAMB3NM_000228.3 linkc.1978C>T p.Arg660* stop_gained, splice_region_variant Exon 15 of 23 ENST00000356082.9 NP_000219.2 Q13751A0A0S2Z3R6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LAMB3ENST00000356082.9 linkc.1978C>T p.Arg660* stop_gained, splice_region_variant Exon 15 of 23 1 NM_000228.3 ENSP00000348384.3 Q13751
LAMB3ENST00000367030.7 linkc.1978C>T p.Arg660* stop_gained, splice_region_variant Exon 15 of 23 1 ENSP00000355997.3 Q13751
LAMB3ENST00000391911.5 linkc.1978C>T p.Arg660* stop_gained, splice_region_variant Exon 14 of 22 1 ENSP00000375778.1 Q13751

Frequencies

GnomAD3 genomes
AF:
0.0000591
AC:
9
AN:
152168
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000193
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:
0.0000200
AC:
5
AN:
249798
AF XY:
0.0000148
show subpopulations
Gnomad AFR exome
AF:
0.000123
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:
0.00000881
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000205
AC:
30
AN:
1460208
Hom.:
0
Cov.:
33
AF XY:
0.0000234
AC XY:
17
AN XY:
726524
show subpopulations
African (AFR)
AF:
0.000299
AC:
10
AN:
33438
American (AMR)
AF:
0.00
AC:
0
AN:
44674
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.000116
AC:
10
AN:
86242
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52134
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5664
European-Non Finnish (NFE)
AF:
0.00000720
AC:
8
AN:
1111880
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60350
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
3
5
8
10
13
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
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
GnomAD4 genome
AF:
0.0000591
AC:
9
AN:
152284
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74456
show subpopulations
African (AFR)
AF:
0.000193
AC:
8
AN:
41550
American (AMR)
AF:
0.00
AC:
0
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.569
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
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:
0.0000407
Hom.:
0
Bravo
AF:
0.0000567
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Junctional epidermolysis bullosa gravis of Herlitz Pathogenic:2
Dec 10, 2018
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: LAMB3 c.1978C>T (p.Arg660X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 2.2e-05 in 275670 control chromosomes (gnomAD). c.1978C>T has been reported in the literature in multiple individuals affected with Junctional Epidermolysis Bullosa (Christiano_1997, Yuen_2011, Varki_2006). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. A ClinVar submission from a clinical diagnostic laboratory (evaluation after 2014) cites the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Jun 30, 2016
Counsyl
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

not provided Pathogenic:2
Aug 12, 2022
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 16473856, 12813757, 8824879, 21801158, 9160387) -

Jan 12, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg660*) in the LAMB3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in LAMB3 are known to be pathogenic (PMID: 11023379, 16473856). This variant is present in population databases (rs146794392, gnomAD 0.02%). This premature translational stop signal has been observed in individuals with autosomal recessive junctional epidermolysis bullosa (PMID: 9160387, 21801158). ClinVar contains an entry for this variant (Variation ID: 189034). For these reasons, this variant has been classified as Pathogenic. -

Junctional epidermolysis bullosa gravis of Herlitz;C0268374:Junctional epidermolysis bullosa, non-Herlitz type;C4011403:Amelogenesis imperfecta type 1A Pathogenic:1
Apr 30, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.43
D
BayesDel_noAF
Pathogenic
0.27
CADD
Pathogenic
44
DANN
Uncertain
0.99
Eigen
Benign
-0.037
Eigen_PC
Benign
-0.38
FATHMM_MKL
Benign
0.20
N
PhyloP100
-0.0050
Vest4
0.57
GERP RS
-0.69
Mutation Taster
=9/191
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00047
dbscSNV1_RF
Benign
0.30
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: rs146794392; hg19: chr1-209797344; API