rs747360831

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 3P and 7B. PM1PP2BP4_ModerateBS1_SupportingBS2

The NM_005359.6(SMAD4):​c.1039A>G​(p.Ile347Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000136 in 1,613,952 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

SMAD4
NM_005359.6 missense

Scores

5
14

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:1

Conservation

PhyloP100: 0.955
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PM1
In a domain MH2 (size 229) in uniprot entity SMAD4_HUMAN there are 40 pathogenic changes around while only 2 benign (95%) in NM_005359.6
PP2
Missense variant in the SMAD4 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 36 curated pathogenic missense variants (we use a threshold of 10). The gene has 52 curated benign missense variants. Gene score misZ: 4.1308 (above the threshold of 3.09). Trascript score misZ: 4.9346 (above the threshold of 3.09). GenCC associations: The gene is linked to familial thoracic aortic aneurysm and aortic dissection, generalized juvenile polyposis/juvenile polyposis coli, hereditary hemorrhagic telangiectasia, Myhre syndrome, pulmonary arterial hypertension, juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome, juvenile polyposis syndrome.
BP4
Computational evidence support a benign effect (MetaRNN=0.10098234).
BS1
Variant frequency is greater than expected in population sas. gnomad4_exome allele frequency = 0.0000144 (21/1461792) while in subpopulation SAS AF= 0.0000812 (7/86254). AF 95% confidence interval is 0.0000376. There are 0 homozygotes in gnomad4_exome. There are 11 alleles in male gnomad4_exome subpopulation. Median coverage is 31. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High AC in GnomAdExome4 at 21 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMAD4NM_005359.6 linkc.1039A>G p.Ile347Val missense_variant Exon 9 of 12 ENST00000342988.8 NP_005350.1 Q13485A0A024R274

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SMAD4ENST00000342988.8 linkc.1039A>G p.Ile347Val missense_variant Exon 9 of 12 5 NM_005359.6 ENSP00000341551.3 Q13485

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152160
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000795
AC:
2
AN:
251440
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135888
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000653
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000144
AC:
21
AN:
1461792
Hom.:
0
Cov.:
31
AF XY:
0.0000151
AC XY:
11
AN XY:
727204
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000812
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000108
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152160
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74310
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000113
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:6Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Uncertain:1
Apr 15, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: SMAD4 c.1039A>G (p.Ile347Val) results in a conservative amino acid change located in the SMAD domain, Dwarfin-type domain (IPR001132) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251440 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.1039A>G in individuals affected with Juvenile Polyposis Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1
Oct 09, 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 does not alter protein structure/function; Identified in individuals with heritable and/or early-onset thoracic aortic disease (Bhave et al., 2021); This variant is associated with the following publications: (PMID: 36243179, 17873119, 18823382, 15235019, 36158166) -

Hereditary cancer-predisposing syndrome Uncertain:1
Feb 14, 2022
Color Diagnostics, LLC DBA Color Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This missense variant replaces isoleucine with valine at codon 347 of the SMAD4 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 2/251440 chromosomes 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. -

Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome Uncertain:1
Dec 07, 2023
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 isoleucine with valine at codon 347 of the SMAD4 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 2/251440 chromosomes 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. -

Juvenile polyposis syndrome;C0796081:Myhre syndrome;C1832942:Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome;C2931038:Familial pancreatic carcinoma Uncertain:1
Feb 23, 2024
Fulgent Genetics, Fulgent Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Juvenile polyposis syndrome Uncertain:1
Jan 26, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 347 of the SMAD4 protein (p.Ile347Val). This variant is present in population databases (rs747360831, gnomAD 0.006%). This missense change has been observed in individual(s) with thoracic aortic disease (PMID: 36158166). ClinVar contains an entry for this variant (Variation ID: 460522). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -

Hereditary cancer-predisposing syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Benign:1
Feb 28, 2022
Ambry Genetics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.053
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Benign
-0.21
CADD
Benign
15
DANN
Benign
0.95
DEOGEN2
Uncertain
0.66
D;D;T
Eigen
Benign
-0.51
Eigen_PC
Benign
-0.29
FATHMM_MKL
Uncertain
0.81
D
LIST_S2
Benign
0.80
.;T;T
M_CAP
Uncertain
0.093
D
MetaRNN
Benign
0.10
T;T;T
MetaSVM
Uncertain
0.20
D
MutationAssessor
Benign
-0.20
N;N;.
PrimateAI
Benign
0.47
T
PROVEAN
Benign
0.21
N;N;.
REVEL
Uncertain
0.39
Sift
Benign
0.73
T;T;.
Sift4G
Benign
0.37
T;T;T
Polyphen
0.0010
B;B;.
Vest4
0.21
MutPred
0.43
Gain of phosphorylation at T349 (P = 0.1776);Gain of phosphorylation at T349 (P = 0.1776);.;
MVP
0.58
MPC
0.38
ClinPred
0.085
T
GERP RS
3.4
Varity_R
0.040
gMVP
0.26

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs747360831; hg19: chr18-48591876; COSMIC: COSV100747983; COSMIC: COSV100747983; API