18-51054892-G-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_005359.6(SMAD4):c.566G>T(p.Arg189Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,784 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R189C) has been classified as Benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SMAD4
NM_005359.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 8.02

Publications

2 publications found

Variant links:

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

SMAD4 links:

ENSG00000267699 (HGNC:):

ENSG00000267699 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

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 link	c.566G>T	p.Arg189Leu	missense_variant	Exon 5 of 12	ENST00000342988.8	NP_005350.1	Q13485A0A024R274

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SMAD4	ENST00000342988.8 link	c.566G>T	p.Arg189Leu	missense_variant	Exon 5 of 12	5	NM_005359.6	ENSP00000341551.3	Q13485
ENSG00000267699	ENST00000590722.2 link	n.*742G>T		non_coding_transcript_exon_variant	Exon 8 of 9	2		ENSP00000465737.1	E7EUB6
ENSG00000267699	ENST00000590722.2 link	n.*742G>T		3_prime_UTR_variant	Exon 8 of 9	2		ENSP00000465737.1	E7EUB6

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461784

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727208

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111910

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection

Uncertain:1

Oct 05, 2020

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R189L variant (also known as c.566G>T), located in coding exon 4 of the SMAD4 gene, results from a G to T substitution at nucleotide position 566. The arginine at codon 189 is replaced by leucine, an amino acid with dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Hereditary cancer-predisposing syndrome

Uncertain:1

Jan 18, 2019

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Juvenile polyposis syndrome

Uncertain:1

Feb 01, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 189 of the SMAD4 protein (p.Arg189Leu). 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: 484813). 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) performed at Invitae indicates that this missense variant is not expected to disrupt SMAD4 protein function with a negative predictive value of 95%. 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

0.20

BayesDel_addAF

Pathogenic

0.17

BayesDel_noAF

Uncertain

0.010

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.51

D;D;T

Eigen

Benign

-0.038

Eigen_PC

Benign

0.19

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

.;D;D

M_CAP

Benign

0.038

MetaRNN

Uncertain

0.62

D;D;D

MetaSVM

Benign

-0.81

MutationAssessor

Benign

1.0

L;L;.

PhyloP100

8.0

PrimateAI

Uncertain

0.62

PROVEAN

Benign

-1.4

N;N;.

REVEL

Benign

0.23

Sift

Benign

0.39

T;T;.

Sift4G

Benign

0.72

T;T;T

Polyphen

0.089

B;B;.

Vest4

0.71

MutPred

0.33

Loss of catalytic residue at R189 (P = 0.0257);Loss of catalytic residue at R189 (P = 0.0257);Loss of catalytic residue at R189 (P = 0.0257);

MVP

0.84

MPC

0.57

ClinPred

0.53

GERP RS

5.9

Varity_R

0.093

gMVP

0.51

Mutation Taster

=79/21

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over