rs770301659

Variant names:

• chr18-51067174-G-A
• rs770301659
• NM_005359.6:c.1295G>A

Your query was ambiguous. Multiple possible variants found:

• chr18-51067174-G-A
• chr18-51067174-G-C
• chr18-51067174-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1 PM2

The NM_005359.6(SMAD4):​c.1295G>A​(p.Ser432Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. S432T) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMAD4 NM_005359.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.82
• Publications: 2 publications found

Genes affected

SMAD4 (HGNC:6770): (SMAD family member 4) This gene encodes a member of the Smad family of signal transduction proteins. Smad proteins are phosphorylated and activated by transmembrane serine-threonine receptor kinases in response to transforming growth factor (TGF)-beta signaling. The product of this gene forms homomeric complexes and heteromeric complexes with other activated Smad proteins, which then accumulate in the nucleus and regulate the transcription of target genes. This protein binds to DNA and recognizes an 8-bp palindromic sequence (GTCTAGAC) called the Smad-binding element (SBE). The protein acts as a tumor suppressor and inhibits epithelial cell proliferation. It may also have an inhibitory effect on tumors by reducing angiogenesis and increasing blood vessel hyperpermeability. The encoded protein is a crucial component of the bone morphogenetic protein signaling pathway. The Smad proteins are subject to complex regulation by post-translational modifications. Mutations or deletions in this gene have been shown to result in pancreatic cancer, juvenile polyposis syndrome, and hereditary hemorrhagic telangiectasia syndrome. [provided by RefSeq, May 2022]

SMAD4 Gene-Disease associations (from GenCC):

• juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Genomics England PanelApp, G2P, PanelApp Australia
• Myhre syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet, G2P, Labcorp Genetics (formerly Invitae)
• generalized juvenile polyposis/juvenile polyposis coli

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• juvenile polyposis syndrome

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hereditary hemorrhagic telangiectasia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• pulmonary arterial hypertension

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a domain MH2 (size 229) in uniprot entity SMAD4_HUMAN there are 34 pathogenic changes around while only 2 benign (94%) in NM_005359.6
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMAD4	NM_005359.6	c.1295G>A	p.Ser432Asn	missense_variant	Exon 10 of 12	ENST00000342988.8	NP_005350.1
SMAD4	NM_001407041.1	c.1295G>A	p.Ser432Asn	missense_variant	Exon 10 of 12		NP_001393970.1
SMAD4	NM_001407042.1	c.1295G>A	p.Ser432Asn	missense_variant	Exon 10 of 12		NP_001393971.1
SMAD4	NR_176265.1	n.1833G>A		non_coding_transcript_exon_variant	Exon 10 of 13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMAD4	ENST00000342988.8	c.1295G>A	p.Ser432Asn	missense_variant	Exon 10 of 12	5	NM_005359.6	ENSP00000341551.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 25

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome Uncertain:1

Nov 30, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Juvenile polyposis syndrome Uncertain:1

Mar 07, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 432 of the SMAD4 protein (p.Ser432Asn). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SMAD4-related conditions. ClinVar contains an entry for this variant (Variation ID: 405498). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SMAD4 protein 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.31
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.90	D;D;D;.
Eigen	Benign	0.070
Eigen_PC	Uncertain	0.28
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	.;D;D;D
M_CAP	Uncertain	0.14	D
MetaRNN	Uncertain	0.51	D;D;D;D
MetaSVM	Uncertain	0.37	D
MutationAssessor	Benign	0.97	L;L;.;.
PhyloP100		9.8
PrimateAI	Pathogenic	0.84	D
PROVEAN	Benign	-1.3	N;N;.;.
REVEL	Uncertain	0.35
Sift	Benign	0.23	T;T;.;.
Sift4G	Benign	0.22	T;T;T;T
Polyphen		0.0	B;B;.;.
Vest4		0.60
MutPred		0.46		Gain of loop (P = 0.0502);Gain of loop (P = 0.0502);.;.;
MVP		0.78
MPC		1.5
ClinPred		0.95	D
GERP RS		5.2
PromoterAI		-0.012	Neutral
Varity_R		0.58
gMVP		0.92
Mutation Taster		=35/65	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: rs770301659; hg19: chr18-48593544;