18-23928148-C-T

Variant names:

Variant summary

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

The NM_198129.4(LAMA3):c.8203C>T(p.Arg2735*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000118 in 1,613,438 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

LAMA3
NM_198129.4 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 4.66

Variant links:

Genes affected

LAMA3 (HGNC:6483): (laminin subunit alpha 3) The protein encoded by this gene belongs to the laminin family of secreted molecules. Laminins are heterotrimeric molecules that consist of alpha, beta, and gamma subunits that assemble through a coiled-coil domain. Laminins are essential for formation and function of the basement membrane and have additional functions in regulating cell migration and mechanical signal transduction. This gene encodes an alpha subunit and is responsive to several epithelial-mesenchymal regulators including keratinocyte growth factor, epidermal growth factor and insulin-like growth factor. Mutations in this gene have been identified as the cause of Herlitz type junctional epidermolysis bullosa and laryngoonychocutaneous syndrome. Alternative splicing and alternative promoter usage result in multiple transcript variants. [provided by RefSeq, Dec 2014]

LAMA3 links:

Genome browser will be placed here

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 18-23928148-C-T is Pathogenic according to our data. Variant chr18-23928148-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 370076.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
LAMA3	NM_198129.4 link	c.8203C>T	p.Arg2735*	stop_gained	Exon 63 of 75	ENST00000313654.14	NP_937762.2	Q16787-2
LAMA3	NM_000227.6 link	c.3376C>T	p.Arg1126*	stop_gained	Exon 26 of 38	ENST00000269217.11	NP_000218.3	Q16787-1A0A0A6YYF2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA3	ENST00000313654.14 link	c.8203C>T	p.Arg2735*	stop_gained	Exon 63 of 75	1	NM_198129.4	ENSP00000324532.8		Q16787-2
LAMA3	ENST00000269217.11 link	c.3376C>T	p.Arg1126*	stop_gained	Exon 26 of 38	1	NM_000227.6	ENSP00000269217.5		Q16787-1A0A0A6YYF2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152092

Hom.:

Cov.:

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

251244

Hom.:

AF XY:

0.0000295

AC XY:

AN XY:

135770

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

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:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000116

AC:

AN:

1461346

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

727028

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000447

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:

0.0000135

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152092

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74284

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:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000278

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Junctional epidermolysis bullosa gravis of Herlitz

Pathogenic:1

Nov 03, 2016

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Pathogenic:1

Jun 25, 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.Arg1126*) in the LAMA3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in LAMA3 are known to be pathogenic (PMID: 10366601, 11810295, 12915477, 16473856, 17362460, 22434185, 23869449, 27827380, 28087116). This variant is present in population databases (rs774133746, gnomAD 0.006%). This premature translational stop signal has been observed in individual(s) with clinical features of junctional epidermolysis bullosa (PMID: 22434185). ClinVar contains an entry for this variant (Variation ID: 370076). For these reasons, this variant has been classified as Pathogenic. -

Epidermolysis bullosa, junctional 2B, severe

Pathogenic:1

May 17, 2022

Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Junctional epidermolysis bullosa

Pathogenic:1

Aug 12, 2022

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: LAMA3 c.3376C>T (p.Arg1126X) 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. Truncations downstream of this position have been observed in the HGMD database. The variant allele was found at a frequency of 2e-05 in 251244 control chromosomes. c.3376C>T has been reported in the literature as a compound heterozygous genotype in at-least one individual affected with Junctional Epidermolysis Bullosa, non-Herlitz (example, Yuen_2012). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.54

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.89

Eigen_PC

Pathogenic

0.79

FATHMM_MKL

Uncertain

0.83

Vest4

0.88

GERP RS

5.8

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over