7-107964660-T-C

Variant names:

• chr7-107964660-T-C
• rs139481973
• NM_002291.3:c.1590A>G

Variant summary

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

The NM_002291.3(LAMB1):​c.1590A>G​(p.Ser530Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,866 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. S530S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: LAMB1 NM_002291.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.887
• Publications: 0 publications found

Genes affected

LAMB1 (HGNC:6486): (laminin subunit beta 1) 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 are composed of 3 non identical chains: laminin alpha, beta and gamma (formerly A, B1, and B2, respectively) and they form 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 beta chain isoform laminin, beta 1. The beta 1 chain has 7 structurally distinct domains which it shares with other beta chain isomers. The C-terminal helical region containing domains I and II are separated by domain alpha, domains III and V contain several EGF-like repeats, and domains IV and VI have a globular conformation. Laminin, beta 1 is expressed in most tissues that produce basement membranes, and is one of the 3 chains constituting laminin 1, the first laminin isolated from Engelbreth-Holm-Swarm (EHS) tumor. A sequence in the beta 1 chain that is involved in cell attachment, chemotaxis, and binding to the laminin receptor was identified and shown to have the capacity to inhibit metastasis. [provided by RefSeq, Aug 2011]

LAMB1 Gene-Disease associations (from GenCC):

• cobblestone lissencephaly without muscular or ocular involvement

  Inheritance: AR, Unknown Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, ClinGen, Orphanet, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)

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=-0.86).
• BP7: Synonymous conserved (PhyloP=-0.887 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002291.3. 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
	LAMB1	NM_002291.3	MANE Select	c.1590A>G	p.Ser530Ser	synonymous	Exon 14 of 34	NP_002282.2	P07942

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LAMB1	ENST00000222399.11	TSL:1 MANE Select	c.1590A>G	p.Ser530Ser	synonymous	Exon 14 of 34	ENSP00000222399.6	P07942
	LAMB1	ENST00000393560.5	TSL:1	c.1590A>G	p.Ser530Ser	synonymous	Exon 14 of 19	ENSP00000377190.1	E7EPA6
	LAMB1	ENST00000943288.1		c.1590A>G	p.Ser530Ser	synonymous	Exon 14 of 34	ENSP00000613347.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461866 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727236

African (AFR) AF: 0.00 AC: 0 AN: 33480

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: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

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

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

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
CADD	Benign	2.2
DANN	Benign	0.47
PhyloP100		-0.89
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs139481973; hg19: chr7-107605105;