18-23857967-G-A

Variant names:

• chr18-23857967-G-A
• rs867449
• NM_198129.4:c.4260G>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_198129.4(LAMA3):​c.4260G>A​(p.Gly1420Gly) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. G1420G) has been classified as Benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: LAMA3 NM_198129.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.294
• Publications: 15 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: G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet
• junctional epidermolysis bullosa Herlitz type

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

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.74).
• BP7: Synonymous conserved (PhyloP=0.294 with no splicing effect.

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMA3	NM_198129.4	MANE Select	c.4260G>A	p.Gly1420Gly	synonymous	Exon 33 of 75	NP_937762.2
	LAMA3	NM_001127717.4		c.4260G>A	p.Gly1420Gly	synonymous	Exon 33 of 74	NP_001121189.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMA3	ENST00000313654.14	TSL:1 MANE Select	c.4260G>A	p.Gly1420Gly	synonymous	Exon 33 of 75	ENSP00000324532.8
	LAMA3	ENST00000399516.7	TSL:1	c.4260G>A	p.Gly1420Gly	synonymous	Exon 33 of 74	ENSP00000382432.2
	LAMA3	ENST00000649721.1		c.1152G>A	p.Gly384Gly	synonymous	Exon 8 of 48	ENSP00000497885.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151986 Hom.: 0 Cov.: 32

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

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461874 Hom.: 0 Cov.: 56 AF XY: 0.00000138 AC XY: 1 AN XY: 727242

African (AFR) AF: 0.00 AC: 0 AN: 33478

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: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

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

European-Non Finnish (NFE) AF: 0.00000540 AC: 6 AN: 1112002

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151986 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74238

African (AFR) AF: 0.00 AC: 0 AN: 41358

American (AMR) AF: 0.00 AC: 0 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10568

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67986

Other (OTH) AF: 0.00 AC: 0 AN: 2082

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.74
CADD	Benign	2.6
DANN	Benign	0.74
PhyloP100		0.29

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

Other links and lift over

dbSNP: rs867449; hg19: chr18-21437931;