18-51054901-C-T

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The NM_005359.6(SMAD4):​c.575C>T​(p.Thr192Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000752 in 1,461,804 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T192A) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

SMAD4
NM_005359.6 missense

Scores

6
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:2

Conservation

PhyloP100: 5.41

Publications

5 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.21193185).
BS2
High AC in GnomAdExome4 at 11 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMAD4NM_005359.6 linkc.575C>T p.Thr192Ile missense_variant Exon 5 of 12 ENST00000342988.8 NP_005350.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SMAD4ENST00000342988.8 linkc.575C>T p.Thr192Ile missense_variant Exon 5 of 12 5 NM_005359.6 ENSP00000341551.3
ENSG00000267699ENST00000590722.2 linkn.*751C>T non_coding_transcript_exon_variant Exon 8 of 9 2 ENSP00000465737.1
ENSG00000267699ENST00000590722.2 linkn.*751C>T 3_prime_UTR_variant Exon 8 of 9 2 ENSP00000465737.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251488
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000397
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000752
AC:
11
AN:
1461804
Hom.:
0
Cov.:
31
AF XY:
0.00000550
AC XY:
4
AN XY:
727208
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.000268
AC:
7
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1111934
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.0000464
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:8Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome Uncertain:3
Apr 10, 2023
Myriad Genetics, Inc.
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -

Nov 03, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 28, 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 threonine with isoleucine at codon 192 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 been reported in an individual affected with breast cancer (PMID: 25186627) and a patient with advanced cancer (PMID: 28873162). This variant has also been identified in 4/251488 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. -

Hereditary cancer-predisposing syndrome Uncertain:2
May 03, 2021
Sema4, Sema4
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

- -

Feb 01, 2023
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces threonine with isoleucine at codon 192 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 been reported in an individual affected with breast cancer (PMID: 25186627) and a patient with advanced cancer (PMID: 28873162). This variant has also been identified in 4/251488 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 Uncertain:1Benign:1
Jun 13, 2017
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Nov 27, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Aug 23, 2024
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.575C>T (p.Thr192Ile) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 251488 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.575C>T has been reported in the literature in individuals affected with cancer without cosegregation information (e.g. Tung_2015, Mandelker_2017). These reports do not provide unequivocal conclusions about association of the variant with Juvenile Polyposis Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 25186627, 28873162). ClinVar contains an entry for this variant (Variation ID: 136076). Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1
Apr 02, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with breast or other cancer (PMID: 25186627, 28873162); This variant is associated with the following publications: (PMID: 25186627, 25742471, 28873162, 15235019, 18823382, 22992590) -

Hereditary cancer-predisposing syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Benign:1
Nov 16, 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
0.12
BayesDel_addAF
Uncertain
0.094
D
BayesDel_noAF
Benign
-0.10
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.59
D;D;T
Eigen
Benign
-0.24
Eigen_PC
Benign
-0.10
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Uncertain
0.88
.;D;D
M_CAP
Benign
0.038
D
MetaRNN
Benign
0.21
T;T;T
MetaSVM
Benign
-0.78
T
MutationAssessor
Benign
1.4
L;L;.
PhyloP100
5.4
PrimateAI
Uncertain
0.56
T
PROVEAN
Benign
-1.6
N;N;.
REVEL
Benign
0.18
Sift
Benign
0.16
T;T;.
Sift4G
Benign
0.20
T;T;T
Polyphen
0.034
B;B;.
Vest4
0.39
MutPred
0.23
Loss of glycosylation at T192 (P = 0.0163);Loss of glycosylation at T192 (P = 0.0163);Loss of glycosylation at T192 (P = 0.0163);
MVP
0.69
MPC
0.51
ClinPred
0.17
T
GERP RS
5.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.073
gMVP
0.34
Mutation Taster
=77/23
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs587780792; hg19: chr18-48581271; COSMIC: COSV61694641; API