15-67181315-G-C

Position:

• chr15-67181315-G-C

Variant summary

Our verdict is Pathogenic. Variant got 21 ACMG points: 21P and 0B. PS1 PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_005902.4(SMAD3):​c.733G>C​(p.Gly245Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin Lovd.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMAD3 NM_005902.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 9.87

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]

ACMG classification

Verdict is Pathogenic. Variant got 21 ACMG points.

• PS1: Transcript NM_005902.4 (SMAD3) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in Lovd
• PM1: In a domain MH2 (size 193) in uniprot entity SMAD3_HUMAN there are 36 pathogenic changes around while only 0 benign (100%) in NM_005902.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SMAD3. . Gene score misZ 3.4782 (greater than the threshold 3.09). Trascript score misZ 4.3526 (greater than threshold 3.09). GenCC has associacion of gene with familial thoracic aortic aneurysm and aortic dissection, aneurysm-osteoarthritis syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant 15-67181315-G-C is Pathogenic according to our data. Variant chr15-67181315-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 520179.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMAD3	NM_005902.4	c.733G>C	p.Gly245Arg	missense_variant	6/9	ENST00000327367.9	NP_005893.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMAD3	ENST00000327367.9	c.733G>C	p.Gly245Arg	missense_variant	6/9	1	NM_005902.4	ENSP00000332973	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 06, 2019	The p.G245R variant (also known as c.733G>C), located in coding exon 6 of the SMAD3 gene, results from a G to C substitution at nucleotide position 733. The glycine at codon 245 is replaced by arginine, an amino acid with dissimilar properties. This alteration was previously reported in a nonsyndromic pediatric patient with a dilated aorta (Arroyave J et al. Cardiol Young, 2018;28:765-767). Internal structural analysis indicates that this variant causes a significant decrease in SMAD3 structural stability (Qin BY et al. Genes Dev. 2002 Aug;16(15):1950-63; Ambry internal data). A likely pathogenic alteration resulting in the same amino acid change (c.733G>A p.G245R) has also been described (Aubart M. PLoS ONE 2014; 9(5):e96387). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 19, 2023	This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 245 of the SMAD3 protein (p.Gly245Arg). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with clinical features of SMAD3-related conditions (PMID: 24804794, 29444731; Invitae). ClinVar contains an entry for this variant (Variation ID: 520179). 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 with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	1.0	D;.;D;.;.;D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	4.1	H;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-7.7	D;D;D;D;D;D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D
Polyphen		1.0	D;.;.;.;.;.;.
Vest4		0.99
MutPred		0.93		Gain of sheet (P = 0.1539);.;.;.;.;.;.;
MVP		0.99
MPC		2.6
ClinPred		1.0	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.97
gMVP		0.90

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

LitVar

Other links and lift over

dbSNP: rs863223737; hg19: chr15-67473653;