chr1-183201813-A-C

Variant names:

• chr1-183201813-A-C
• rs1028771
• NM_005562.3:c.80-6068A>C

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_Strong BS1 BS2

The NM_005562.3(LAMC2):​c.80-6068A>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00593 in 152,332 control chromosomes in the GnomAD database, including 8 homozygotes. 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 0.0059 (8 hom., cov: 32)
• Consequence: LAMC2 NM_005562.3 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.240
• Publications: 10 publications found

Genes affected

LAMC2 (HGNC:6493): (laminin subunit gamma 2) Laminins, a family of extracellular matrix glycoproteins, are the major noncollagenous constituent of basement membranes. They have been implicated in a wide variety of biological processes including cell adhesion, differentiation, migration, signaling, neurite outgrowth and metastasis. Laminins, composed of 3 non identical chains: laminin alpha, beta and gamma (formerly A, B1, and B2, respectively), have a cruciform structure consisting of 3 short arms, each formed by a different chain, and a long arm composed of all 3 chains. Each laminin chain is a multidomain protein encoded by a distinct gene. Several isoforms of each chain have been described. Different alpha, beta and gamma chain isomers combine to give rise to different heterotrimeric laminin isoforms which are designated by Arabic numerals in the order of their discovery, i.e. alpha1beta1gamma1 heterotrimer is laminin 1. The biological functions of the different chains and trimer molecules are largely unknown, but some of the chains have been shown to differ with respect to their tissue distribution, presumably reflecting diverse functions in vivo. This gene encodes the gamma chain isoform laminin, gamma 2. The gamma 2 chain, formerly thought to be a truncated version of beta chain (B2t), is highly homologous to the gamma 1 chain; however, it lacks domain VI, and domains V, IV and III are shorter. It is expressed in several fetal tissues but differently from gamma 1, and is specifically localized to epithelial cells in skin, lung and kidney. The gamma 2 chain together with alpha 3 and beta 3 chains constitute laminin 5 (earlier known as kalinin), which is an integral part of the anchoring filaments that connect epithelial cells to the underlying basement membrane. The epithelium-specific expression of the gamma 2 chain implied its role as an epithelium attachment molecule, and mutations in this gene have been associated with junctional epidermolysis bullosa, a skin disease characterized by blisters due to disruption of the epidermal-dermal junction. Two transcript variants resulting from alternative splicing of the 3' terminal exon, and encoding different isoforms of gamma 2 chain, have been described. The two variants are differentially expressed in embryonic tissues, however, the biological significance of the two forms is not known. Transcript variants utilizing alternative polyA_signal have also been noted in literature. [provided by RefSeq, Aug 2011]

LAMC2 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: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp
• 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: Benign. The variant received -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.91).
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00593 (904/152332) while in subpopulation AFR AF = 0.0208 (863/41578). AF 95% confidence interval is 0.0196. There are 8 homozygotes in GnomAd4. There are 447 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
• BS2: High Homozygotes in GnomAd4 at 8 AR gene

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005562.3. 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
	LAMC2	NM_005562.3	MANE Select	c.80-6068A>C		intron	N/A	NP_005553.2	Q13753-1
	LAMC2	NM_018891.3		c.80-6068A>C		intron	N/A	NP_061486.2	Q13753-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMC2	ENST00000264144.5	TSL:1 MANE Select	c.80-6068A>C		intron	N/A	ENSP00000264144.4	Q13753-1
	LAMC2	ENST00000493293.5	TSL:1	c.80-6068A>C		intron	N/A	ENSP00000432063.1	Q13753-2
	LAMC2	ENST00000914499.1		c.80-6068A>C		intron	N/A	ENSP00000584558.1

Frequencies

GnomAD3 genomes AF: 0.00592 AC: 901 AN: 152214 Hom.: 8 Cov.: 32

Gnomad AFR AF: 0.0207

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00196

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00431

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.00593 AC: 904 AN: 152332 Hom.: 8 Cov.: 32 AF XY: 0.00600 AC XY: 447 AN XY: 74500

African (AFR) AF: 0.0208 AC: 863 AN: 41578

American (AMR) AF: 0.00196 AC: 30 AN: 15306

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 292

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68026

Other (OTH) AF: 0.00426 AC: 9 AN: 2112

Alfa AF: 0.00237 Hom.: 9

Bravo AF: 0.00682

Asia WGS AF: 0.00202 AC: 8 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.91
CADD	Benign	3.1
DANN	Benign	0.57
PhyloP100		0.24

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: rs1028771; hg19: chr1-183170948;