chr1-209634547-G-GA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000228.3(LAMB3):​c.463_464insT​(p.Ser155PhefsTer27) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000384 in 1,614,024 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (β˜…β˜…). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000040 ( 0 hom. )

Consequence

LAMB3
NM_000228.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: -0.674
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-209634547-G-GA is Pathogenic according to our data. Variant chr1-209634547-G-GA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188937.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
LAMB3NM_000228.3 linkuse as main transcriptc.463_464insT p.Ser155PhefsTer27 frameshift_variant 6/23 ENST00000356082.9 NP_000219.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
LAMB3ENST00000356082.9 linkuse as main transcriptc.463_464insT p.Ser155PhefsTer27 frameshift_variant 6/231 NM_000228.3 ENSP00000348384 P1
LAMB3ENST00000367030.7 linkuse as main transcriptc.463_464insT p.Ser155PhefsTer27 frameshift_variant 6/231 ENSP00000355997 P1
LAMB3ENST00000391911.5 linkuse as main transcriptc.463_464insT p.Ser155PhefsTer27 frameshift_variant 5/221 ENSP00000375778 P1
LAMB3ENST00000415782.1 linkuse as main transcriptc.463_464insT p.Ser155PhefsTer27 frameshift_variant 6/62 ENSP00000388960

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152136
Hom.:
0
Cov.:
31
show subpopulations
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000159
AC:
4
AN:
251300
Hom.:
0
AF XY:
0.0000294
AC XY:
4
AN XY:
135848
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000404
AC:
59
AN:
1461888
Hom.:
0
Cov.:
32
AF XY:
0.0000371
AC XY:
27
AN XY:
727244
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000522
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152136
Hom.:
0
Cov.:
31
AF XY:
0.0000135
AC XY:
1
AN XY:
74326
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000441
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000151

ClinVar

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

Submissions by phenotype

not provided Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJul 12, 2022This sequence change creates a premature translational stop signal (p.Ser155Phefs*27) 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 (rs776537364, gnomAD 0.004%). This premature translational stop signal has been observed in individual(s) with junctional epidermolysis bullosa (PMID: 8824879, 11023379; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 188937). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingGeneDxJun 20, 2023Frameshift 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; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 9160387, 8824879, 11023379) -
Junctional epidermolysis bullosa gravis of Herlitz Pathogenic:2
Likely pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpNov 13, 2017Variant summary: The LAMB3 c.463dupT (p.Ser155PhefsX27) variant results in a premature termination codon, predicted to cause a truncated or absent LAMB3 protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory (e.g. c.1365_1366delCA, p.Asn456fsX7; c.1903C>T, p.Arg635X). One in silico tool predicts a damaging outcome for this variant. This variant was found in 4/246120 control chromosomes at a frequency of 0.0000163, which does not exceed the estimated maximal expected allele frequency of a pathogenic LAMB3 variant (0.0009317). The variant has been reported in at least 3 affected individuals in the literature. In addition, one clinical diagnostic laboratory/reputable database classified this variant as likely pathogenic. Taken together, this variant is classified as likely pathogenic. -
Likely pathogenic, criteria provided, single submitterliterature onlyCounsylAug 25, 2014- -
Junctional epidermolysis bullosa gravis of Herlitz;C0268374:Junctional epidermolysis bullosa, non-Herlitz type;C4011403:Amelogenesis imperfecta type 1A Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsMar 21, 2022- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.12
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs776537364; hg19: chr1-209807892; API