1-209615300-G-T

Variant names:

• chr1-209615300-G-T
• rs540971405
• NM_000228.3:c.3490C>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000228.3(LAMB3):​c.3490C>A​(p.Arg1164Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,780 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1164H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: LAMB3 NM_000228.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.82
• Publications: 5 publications found

Genes affected

LAMB3 (HGNC:6490): (laminin subunit beta 3) The product encoded by this gene is a laminin that belongs to a family of basement membrane proteins. This protein is a beta subunit laminin, which together with an alpha and a gamma subunit, forms laminin-5. Mutations in this gene cause epidermolysis bullosa junctional Herlitz type, and generalized atrophic benign epidermolysis bullosa, diseases that are characterized by blistering of the skin. Multiple alternatively spliced transcript variants that encode the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

LAMB3 Gene-Disease associations (from GenCC):

• junctional epidermolysis bullosa

  Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
• junctional epidermolysis bullosa Herlitz type

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

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Genomics England PanelApp, Ambry Genetics
• amelogenesis imperfecta type 1A

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• amelogenesis imperfecta type 1

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• generalized junctional epidermolysis bullosa non-Herlitz type

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.825

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMB3	NM_000228.3	c.3490C>A	p.Arg1164Ser	missense_variant	Exon 23 of 23	ENST00000356082.9	NP_000219.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMB3	ENST00000356082.9	c.3490C>A	p.Arg1164Ser	missense_variant	Exon 23 of 23	1	NM_000228.3	ENSP00000348384.3
LAMB3	ENST00000367030.7	c.3490C>A	p.Arg1164Ser	missense_variant	Exon 23 of 23	1		ENSP00000355997.3
LAMB3	ENST00000391911.5	c.3490C>A	p.Arg1164Ser	missense_variant	Exon 22 of 22	1		ENSP00000375778.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461780 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 727196

⚠️ 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: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

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

European-Finnish (FIN) AF: 0.0000187 AC: 1 AN: 53356

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111978

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

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.044843), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.58
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Benign	-0.090
CADD	Uncertain	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.30	T;T;T
Eigen	Uncertain	0.39
Eigen_PC	Uncertain	0.34
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.81	.;T;.
M_CAP	Benign	0.044	D
MetaRNN	Pathogenic	0.82	D;D;D
MetaSVM	Benign	-0.87	T
MutationAssessor	Uncertain	2.5	M;M;M
PhyloP100		4.8
PrimateAI	Uncertain	0.55	T
PROVEAN	Benign	-2.0	N;N;N
REVEL	Benign	0.28
Sift	Uncertain	0.0020	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;D;D
Vest4		0.65
MutPred		0.54		Loss of MoRF binding (P = 0.0108);Loss of MoRF binding (P = 0.0108);Loss of MoRF binding (P = 0.0108);
MVP		0.81
MPC		0.55
ClinPred		0.91	D
GERP RS		5.6
Varity_R		0.38
gMVP		0.79
Mutation Taster		=61/39	polymorphism

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

Other links and lift over

dbSNP: rs540971405; hg19: chr1-209788645;