NM_000228.3:c.*275C>T

Variant names:

• chr1-209614996-G-A
• rs188120955
• NM_000228.3:c.*275C>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_000228.3(LAMB3):​c.*275C>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000137 in 438,624 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00016 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00013 (0 hom.)
• Consequence: LAMB3 NM_000228.3 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.274
• 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: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.82).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMB3	NM_000228.3	c.*275C>T		3_prime_UTR_variant	Exon 23 of 23	ENST00000356082.9	NP_000219.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMB3	ENST00000356082.9	c.*275C>T		3_prime_UTR_variant	Exon 23 of 23	1	NM_000228.3	ENSP00000348384.3
LAMB3	ENST00000367030.7	c.*275C>T		3_prime_UTR_variant	Exon 23 of 23	1		ENSP00000355997.3
LAMB3	ENST00000391911.5	c.*275C>T		3_prime_UTR_variant	Exon 22 of 22	1		ENSP00000375778.1

Frequencies

GnomAD3 genomes AF: 0.000158 AC: 24 AN: 152200 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

Gnomad ASJ AF: 0.000576

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000250

Gnomad OTH AF: 0.000480

GnomAD4 exome AF: 0.000126 AC: 36 AN: 286306 Hom.: 0 Cov.: 3 AF XY: 0.000169 AC XY: 25 AN XY: 147584

African (AFR) AF: 0.000118 AC: 1 AN: 8500

American (AMR) AF: 0.00 AC: 0 AN: 10936

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 9704

East Asian (EAS) AF: 0.00 AC: 0 AN: 20928

South Asian (SAS) AF: 0.00 AC: 0 AN: 20466

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 19824

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 1418

European-Non Finnish (NFE) AF: 0.000193 AC: 34 AN: 176326

Other (OTH) AF: 0.0000549 AC: 1 AN: 18204

GnomAD4 genome AF: 0.000158 AC: 24 AN: 152318 Hom.: 0 Cov.: 33 AF XY: 0.000201 AC XY: 15 AN XY: 74490

African (AFR) AF: 0.0000241 AC: 1 AN: 41568

American (AMR) AF: 0.000196 AC: 3 AN: 15298

Ashkenazi Jewish (ASJ) AF: 0.000576 AC: 2 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5186

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

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

European-Non Finnish (NFE) AF: 0.000250 AC: 17 AN: 68032

Other (OTH) AF: 0.000475 AC: 1 AN: 2106

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.000128

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Junctional epidermolysis bullosa Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
CADD	Benign	3.3
DANN	Benign	0.63
PhyloP100		-0.27

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: rs188120955; hg19: chr1-209788341;