15-67066344-T-C

Variant names:

• chr15-67066344-T-C
• rs1060500768
• NM_005902.4:c.190T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_005902.4(SMAD3):​c.190T>C​(p.Cys64Arg) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C64Y) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMAD3 NM_005902.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.94
• Publications: 0 publications found

Genes affected

SMAD3 (HGNC:6769): (SMAD family member 3) The SMAD family of proteins are a group of intracellular signal transducer proteins similar to the gene products of the Drosophila gene 'mothers against decapentaplegic' (Mad) and the C. elegans gene Sma. The SMAD3 protein functions in the transforming growth factor-beta signaling pathway, and transmits signals from the cell surface to the nucleus, regulating gene activity and cell proliferation. This protein forms a complex with other SMAD proteins and binds DNA, functioning both as a transcription factor and tumor suppressor. Mutations in this gene are associated with aneurysms-osteoarthritis syndrome and Loeys-Dietz Syndrome 3. [provided by RefSeq, May 2022]

SMAD3 Gene-Disease associations (from GenCC):

• aneurysm-osteoarthritis syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Genomics England PanelApp, Orphanet, G2P, ClinGen, Labcorp Genetics (formerly Invitae)
• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 23 uncertain in NM_005902.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMAD3	NM_005902.4	c.190T>C	p.Cys64Arg	missense_variant	Exon 1 of 9	ENST00000327367.9	NP_005893.1
SMAD3	NM_001407011.1	c.190T>C	p.Cys64Arg	missense_variant	Exon 1 of 10		NP_001393940.1
SMAD3	NM_001407012.1	c.190T>C	p.Cys64Arg	missense_variant	Exon 1 of 8		NP_001393941.1
SMAD3	NM_001407013.1	c.190T>C	p.Cys64Arg	missense_variant	Exon 1 of 8		NP_001393942.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMAD3	ENST00000327367.9	c.190T>C	p.Cys64Arg	missense_variant	Exon 1 of 9	1	NM_005902.4	ENSP00000332973.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1

May 29, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (Invitae) indicates that this missense variant is expected to disrupt SMAD3 function. ClinVar contains an entry for this variant (Variation ID: 405564). This variant has not been reported in the literature in individuals affected with SMAD3-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 64 of the SMAD3 protein (p.Cys64Arg). -

not provided Uncertain:1

Oct 08, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.96	D
Eigen	Uncertain	0.36
Eigen_PC	Uncertain	0.39
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.91	D
M_CAP	Pathogenic	0.52	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Uncertain	0.69	D
MutationAssessor	Pathogenic	3.8	H
PhyloP100		5.9
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-11	D
REVEL	Pathogenic	0.86
Sift	Uncertain	0.0030	D
Sift4G	Pathogenic	0.0010	D
Polyphen		0.046	B
Vest4		0.96
MutPred		0.94		Gain of MoRF binding (P = 0.0175);
MVP		0.99
MPC		2.5
ClinPred		1.0	D
GERP RS		4.2
Varity_R		0.96
gMVP		0.99
Mutation Taster		=10/90	disease causing

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: rs1060500768; hg19: chr15-67358682;