18-23714041-A-G

Position:

• chr18-23714041-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_198129.4(LAMA3):​c.416A>G​(p.Asn139Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,860 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: LAMA3 NM_198129.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.43

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMA3	NM_198129.4	c.416A>G	p.Asn139Ser	missense_variant	2/75	ENST00000313654.14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMA3	ENST00000313654.14	c.416A>G	p.Asn139Ser	missense_variant	2/75	1	NM_198129.4	P1
LAMA3	ENST00000399516.7	c.416A>G	p.Asn139Ser	missense_variant	2/74	1
LAMA3	ENST00000585600.5	c.416A>G	p.Asn139Ser	missense_variant	2/13	1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461860 Hom.: 0 Cov.: 34 AF XY: 0.00000413 AC XY: 3 AN XY: 727240

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 30

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 17, 2024

The c.416A>G (p.N139S) alteration is located in exon 2 (coding exon 2) of the LAMA3 gene. This alteration results from a A to G substitution at nucleotide position 416, causing the asparagine (N) at amino acid position 139 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.022	T
BayesDel_noAF	Benign	-0.27
CADD	Benign	23
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.070	.;T
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.91	.;D
M_CAP	Benign	0.044	D
MetaRNN	Uncertain	0.54	D;D
MetaSVM	Uncertain	0.21	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Benign	0.45	T
PROVEAN	Uncertain	-3.6	D;D
REVEL	Uncertain	0.53
Sift	Uncertain	0.016	D;D
Vest4		0.50
MutPred		0.52		Gain of disorder (P = 0.0788);Gain of disorder (P = 0.0788);
MVP		0.79
MPC		0.49
ClinPred		0.97	D
GERP RS		5.7
gMVP		0.50

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

Publications

LitVar

Other links and lift over

dbSNP: rs1458860166; hg19: chr18-21294005;