NM_005902.4:c.682G>A

Variant names:

• chr15-67181264-G-A
• rs863223735
• NM_005902.4:c.682G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_005902.4(SMAD3):​c.682G>A​(p.Glu228Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SMAD3 NM_005902.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 9.87
• Publications: 1 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: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.911

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMAD3	NM_005902.4	c.682G>A	p.Glu228Lys	missense_variant	Exon 6 of 9	ENST00000327367.9	NP_005893.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMAD3	ENST00000327367.9	c.682G>A	p.Glu228Lys	missense_variant	Exon 6 of 9	1	NM_005902.4	ENSP00000332973.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460860 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726732

African (AFR) AF: 0.00 AC: 0 AN: 33454

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86190

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53356

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5010

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111982

Other (OTH) AF: 0.00 AC: 0 AN: 60314

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1

Oct 15, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 228 of the SMAD3 protein (p.Glu228Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SMAD3-related conditions. ClinVar contains an entry for this variant (Variation ID: 213759). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (Invitae) indicates that this missense variant is not expected to disrupt SMAD3 function. 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. -

not provided Uncertain:1

Nov 09, 2015

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The E228K variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. However, it has been observed in one other individual who had DNA-based testing for TAAD-related disorders at GeneDx. The E228K variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The E228K variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. Moreover, this substitution occurs at a position that is conserved across species, and, consequently, in silico analysis predicts this variant is probably damaging to the protein structure/function. However, no missense variants in nearby residues have been reported in the Human Gene Mutation Database (Stenson et al., 2014), indicating that this region of the gene is not known to harbor disease-causing variants. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Aneurysm-osteoarthritis syndrome Uncertain:1

Jul 29, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces glutamic acid with lysine at codon 228 of the SMAD3 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with SMAD3-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.84	D;.;T;.;.;T;.
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D;D
M_CAP	Pathogenic	0.70	D
MetaRNN	Pathogenic	0.91	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	M;.;.;.;.;.;.
PhyloP100		9.9
PrimateAI	Pathogenic	0.89	D
PROVEAN	Uncertain	-3.8	D;D;D;D;D;D;D
REVEL	Pathogenic	0.92
Sift	Uncertain	0.0010	D;D;D;D;D;D;D
Sift4G	Uncertain	0.052	T;T;D;T;T;D;D
Polyphen		1.0	D;.;.;.;.;.;.
Vest4		0.84
MutPred		0.66		Gain of methylation at E228 (P = 1e-04);.;.;.;.;.;.;
MVP		0.95
MPC		2.5
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.93
gMVP		0.90
Mutation Taster		=6/94	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: rs863223735; hg19: chr15-67473602; COSMIC: COSV59281820;