18-23816593-C-G

Variant names:

• chr18-23816593-C-G
• rs12608087
• NM_198129.4:c.2147+106C>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_198129.4(LAMA3):​c.2147+106C>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000325 in 921,688 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.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000013 (0 hom.)
• Consequence: LAMA3 NM_198129.4 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0380
• Publications: 4 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 -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.88).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMA3	NM_198129.4	c.2147+106C>G		intron_variant	Intron 18 of 74	ENST00000313654.14	NP_937762.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA3	ENST00000313654.14	c.2147+106C>G		intron_variant	Intron 18 of 74	1	NM_198129.4	ENSP00000324532.8
LAMA3	ENST00000399516.7	c.2147+106C>G		intron_variant	Intron 18 of 73	1		ENSP00000382432.2

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 152042 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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000130 AC: 1 AN: 769646 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 403526

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 19880

American (AMR) AF: 0.00 AC: 0 AN: 35540

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 21272

East Asian (EAS) AF: 0.00 AC: 0 AN: 33294

South Asian (SAS) AF: 0.00 AC: 0 AN: 67262

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 38532

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4492

European-Non Finnish (NFE) AF: 0.00000195 AC: 1 AN: 511628

Other (OTH) AF: 0.00 AC: 0 AN: 37746

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 152042 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74256

African (AFR) AF: 0.00 AC: 0 AN: 41386

American (AMR) AF: 0.00 AC: 0 AN: 15266

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5172

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10592

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

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68018

Other (OTH) AF: 0.00 AC: 0 AN: 2084

Alfa AF: 0.00 Hom.: 1407

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.88
CADD	Benign	0.70
DANN	Benign	0.32
PhyloP100		-0.038

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: rs12608087; hg19: chr18-21396557;