9-131009312-A-C

Variant summary

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

The NM_006059.4(LAMC3):c.98A>C(p.Gln33Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: LAMC3 NM_006059.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.12

Genes affected

LAMC3 (HGNC:6494): (laminin subunit gamma 3) 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 gamma chain isoform laminin, gamma 3. The gamma 3 chain is most similar to the gamma 1 chain, and contains all the 6 domains expected of the gamma chain. It is a component of laminin 12. The gamma 3 chain is broadly expressed in skin, heart, lung, and the reproductive tracts. In skin, it is seen within the basement membrane of the dermal-epidermal junction at points of nerve penetration. Gamma 3 is also a prominent element of the apical surface of ciliated epithelial cells of lung, oviduct, epididymis, ductus deferens, and seminiferous tubules. The distribution of gamma 3-containing laminins along ciliated epithelial surfaces suggests that the apical laminins are important in the morphogenesis and structural stability of the ciliated processes of these cells. [provided by RefSeq, Aug 2011]

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
LAMC3	NM_006059.4	c.98A>C	p.Gln33Pro	missense_variant	1/28	ENST00000361069.9
LAMC3	XM_011518121.2	c.98A>C	p.Gln33Pro	missense_variant	1/28
LAMC3	XM_006716921.3	c.98A>C	p.Gln33Pro	missense_variant	1/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMC3	ENST00000361069.9	c.98A>C	p.Gln33Pro	missense_variant	1/28	2	NM_006059.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

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

Mar 16, 2022

The c.98A>C (p.Q33P) alteration is located in exon 1 (coding exon 1) of the LAMC3 gene. This alteration results from a A to C substitution at nucleotide position 98, causing the glutamine (Q) at amino acid position 33 to be replaced by a proline (P). 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	Uncertain	0.50
BayesDel_addAF	Benign	-0.066	T
BayesDel_noAF	Benign	-0.33
Cadd	Uncertain	23
Dann	Uncertain	0.99
DEOGEN2	Benign	0.27	T
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.29
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Benign	0.71	T
M_CAP	Pathogenic	0.41	D
MetaRNN	Uncertain	0.47	T
MetaSVM	Benign	-0.69	T
MutationAssessor	Pathogenic	3.4	M
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-4.4	D
REVEL	Benign	0.27
Sift	Uncertain	0.0040	D
Sift4G	Uncertain	0.020	D
Polyphen		1.0	D
Vest4		0.39
MutPred		0.58		Gain of catalytic residue at P32 (P = 0.0133);
MVP		0.70
MPC		0.53
ClinPred		0.99	D
GERP RS		3.7
Varity_R		0.90
gMVP		0.87

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: chr9-133884699;