rs777292177

Variant names:

• chr1-209617933-GA-G
• rs777292177
• NM_000228.3:c.3024delT

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PP5_Moderate

The NM_000228.3(LAMB3):​c.3024delT​(p.Arg1009GlyfsTer21) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,614,084 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000020 (0 hom.)
• Consequence: LAMB3 NM_000228.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: -1.87
• Publications: 0 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 1-209617933-GA-G is Pathogenic according to our data. Variant chr1-209617933-GA-G is described in ClinVar as Pathogenic. ClinVar VariationId is 370321.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000228.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMB3	NM_000228.3	MANE Select	c.3024delT	p.Arg1009GlyfsTer21	frameshift	Exon 20 of 23	NP_000219.2
	LAMB3	NM_001017402.2		c.3024delT	p.Arg1009GlyfsTer21	frameshift	Exon 19 of 22	NP_001017402.1
	LAMB3	NM_001127641.1		c.3024delT	p.Arg1009GlyfsTer21	frameshift	Exon 20 of 23	NP_001121113.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMB3	ENST00000356082.9	TSL:1 MANE Select	c.3024delT	p.Arg1009GlyfsTer21	frameshift	Exon 20 of 23	ENSP00000348384.3
	LAMB3	ENST00000367030.7	TSL:1	c.3024delT	p.Arg1009GlyfsTer21	frameshift	Exon 20 of 23	ENSP00000355997.3
	LAMB3	ENST00000391911.5	TSL:1	c.3024delT	p.Arg1009GlyfsTer21	frameshift	Exon 19 of 22	ENSP00000375778.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152190 Hom.: 0 Cov.: 33

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: 0.0000517 AC: 13 AN: 251478 AF XY: 0.0000515

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: 0.000185

Gnomad NFE exome AF: 0.0000791

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000198 AC: 29 AN: 1461894 Hom.: 0 Cov.: 33 AF XY: 0.0000151 AC XY: 11 AN XY: 727248

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: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.000150 AC: 8 AN: 53420

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

European-Non Finnish (NFE) AF: 0.0000153 AC: 17 AN: 1112012

Other (OTH) AF: 0.0000662 AC: 4 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152190 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74364

African (AFR) AF: 0.00 AC: 0 AN: 41438

American (AMR) AF: 0.00 AC: 0 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4838

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68040

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

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Mar 17, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This sequence change creates a premature translational stop signal (p.Arg1009Glyfs*21) in the LAMB3 gene. It is expected to result in an absent or disrupted protein product. This variant is present in population databases (rs777292177, ExAC 0.03%). This variant has been observed in individual(s) with epidermolysis bullosa (PMID: 11023379). ClinVar contains an entry for this variant (Variation ID: 370321). Loss-of-function variants in LAMB3 are known to be pathogenic (PMID: 11023379, 16473856).

Junctional epidermolysis bullosa gravis of Herlitz Pathogenic:1

Jan 15, 2016

Counsyl

Significance: Likely 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.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-1.9
Mutation Taster		=13/187	disease causing (ClinVar)

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: rs777292177; hg19: chr1-209791278;