NM_198129.4:c.8177+2T>G

Variant names:

• chr18-23921587-T-G
• rs786204732
• NM_198129.4:c.8177+2T>G

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_198129.4(LAMA3):​c.8177+2T>G variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.000013 in 1,461,492 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 predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: LAMA3 NM_198129.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 5.39
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• junctional epidermolysis bullosa

  Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
• laryngo-onycho-cutaneous syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
• junctional epidermolysis bullosa Herlitz type

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet
• junctional epidermolysis bullosa, non-Herlitz type

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
• generalized junctional epidermolysis bullosa non-Herlitz type

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 18-23921587-T-G is Pathogenic according to our data. Variant chr18-23921587-T-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 189152.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_198129.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMA3	NM_198129.4	MANE Select	c.8177+2T>G		splice_donor intron	N/A	NP_937762.2	Q16787-2
	LAMA3	NM_000227.6	MANE Plus Clinical	c.3350+2T>G		splice_donor intron	N/A	NP_000218.3
	LAMA3	NM_001127717.4		c.8009+2T>G		splice_donor intron	N/A	NP_001121189.2	A0A0A0MSA0

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMA3	ENST00000313654.14	TSL:1 MANE Select	c.8177+2T>G		splice_donor intron	N/A	ENSP00000324532.8	Q16787-2
	LAMA3	ENST00000269217.11	TSL:1 MANE Plus Clinical	c.3350+2T>G		splice_donor intron	N/A	ENSP00000269217.5	Q16787-1
	LAMA3	ENST00000399516.7	TSL:1	c.8009+2T>G		splice_donor intron	N/A	ENSP00000382432.2	Q16787-3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000130 AC: 19 AN: 1461492 Hom.: 0 Cov.: 31 AF XY: 0.0000124 AC XY: 9 AN XY: 727080

African (AFR) AF: 0.00 AC: 0 AN: 33468

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39640

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53308

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.0000171 AC: 19 AN: 1111834

Other (OTH) AF: 0.00 AC: 0 AN: 60382

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
1	-	-	Junctional epidermolysis bullosa gravis of Herlitz (1)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	30
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.97	D
PhyloP100		5.4
GERP RS		5.8
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: -2

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

Other links and lift over

dbSNP: rs786204732; hg19: chr18-21501551;