chr1-183023804-G-T

Position:

• chr1-183023804-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_002293.4(LAMC1):​c.88G>T​(p.Ala30Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: LAMC1 NM_002293.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.52

Genes affected

LAMC1 (HGNC:6492): (laminin subunit gamma 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, 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 1. The gamma 1 chain, formerly thought to be a beta chain, contains structural domains similar to beta chains, however, lacks the short alpha region separating domains I and II. The structural organization of this gene also suggested that it had diverged considerably from the beta chain genes. Embryos of transgenic mice in which both alleles of the gamma 1 chain gene were inactivated by homologous recombination, lacked basement membranes, indicating that laminin, gamma 1 chain is necessary for laminin heterotrimer assembly. It has been inferred by analogy with the strikingly similar 3' UTR sequence in mouse laminin gamma 1 cDNA, that multiple polyadenylation sites are utilized in human to generate the 2 different sized mRNAs (5.5 and 7.5 kb) seen on Northern analysis. [provided by RefSeq, Aug 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.08940068).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMC1	NM_002293.4	c.88G>T	p.Ala30Ser	missense_variant	1/28	ENST00000258341.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMC1	ENST00000258341.5	c.88G>T	p.Ala30Ser	missense_variant	1/28	1	NM_002293.4	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 11, 2023

The c.88G>T (p.A30S) alteration is located in exon 1 (coding exon 1) of the LAMC1 gene. This alteration results from a G to T substitution at nucleotide position 88, causing the alanine (A) at amino acid position 30 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	0.13
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.43
CADD	Benign	20
DANN	Benign	0.90
DEOGEN2	Benign	0.068	T
Eigen	Benign	-0.78
Eigen_PC	Benign	-0.70
FATHMM_MKL	Benign	0.0086	N
LIST_S2	Benign	0.32	T
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.089	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.1	L
MutationTaster	Benign	1.0	N
PrimateAI	Pathogenic	0.85	D
PROVEAN	Benign	-0.25	N
REVEL	Benign	0.033
Sift	Benign	0.46	T
Sift4G	Benign	0.73	T
Polyphen		0.079	B
Vest4		0.14
MutPred		0.38		Gain of glycosylation at A30 (P = 0.0041);
MVP		0.40
MPC		1.0
ClinPred		0.24	T
GERP RS		2.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.7
Varity_R		0.069
gMVP		0.19

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-182992939;