18-51058436-C-T

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP6BS2

The NM_005359.6(SMAD4):​c.884C>T​(p.Pro295Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000192 in 1,613,400 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. P295T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

SMAD4
NM_005359.6 missense

Scores

11
8

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:2

Conservation

PhyloP100: 3.60

Publications

6 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 -5 ACMG points.

BP6
Variant 18-51058436-C-T is Benign according to our data. Variant chr18-51058436-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 240155.
BS2
High AC in GnomAdExome4 at 28 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMAD4NM_005359.6 linkc.884C>T p.Pro295Leu missense_variant Exon 7 of 12 ENST00000342988.8 NP_005350.1 Q13485A0A024R274

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SMAD4ENST00000342988.8 linkc.884C>T p.Pro295Leu missense_variant Exon 7 of 12 5 NM_005359.6 ENSP00000341551.3 Q13485

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
151920
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000576
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000481
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
251480
AF XY:
0.0000294
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.000198
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000192
AC:
28
AN:
1461480
Hom.:
0
Cov.:
32
AF XY:
0.0000248
AC XY:
18
AN XY:
727078
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.000459
AC:
12
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000990
AC:
11
AN:
1111630
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.461
Heterozygous variant carriers
0
2
4
5
7
9
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
AF:
0.0000197
AC:
3
AN:
151920
Hom.:
0
Cov.:
32
AF XY:
0.0000270
AC XY:
2
AN XY:
74196
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41374
American (AMR)
AF:
0.00
AC:
0
AN:
15268
Ashkenazi Jewish (ASJ)
AF:
0.000576
AC:
2
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4814
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10512
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67990
Other (OTH)
AF:
0.000481
AC:
1
AN:
2080
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00131091), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.392
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000480
Hom.:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:6Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2
Mar 19, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The SMAD4 c.884C>T; p.Pro295Leu variant (rs370176106), to our knowledge, is not reported in the medical literature but is reported in ClinVar (Variation ID: 240155). This variant is found in the general population with an overall allele frequency of 0.002% (5/251,480 alleles) in the Genome Aggregation Database (v2.1.1). Computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.53). Due to limited information, the clinical significance of the p.Pro295Leu variant is uncertain at this time. -

Apr 19, 2024
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 indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 30267214, 10636916) -

Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome Uncertain:2
Sep 12, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 25, 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 proline with leucine at codon 295 of the SMAD4 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 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 SMAD4-related disorders in the literature, and has been reported in unaffected individuals (PMID: 30267214, 32459922). This variant has been identified in 5/251480 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. -

not specified Uncertain:1
Apr 21, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1
Mar 28, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces proline with leucine at codon 295 of the SMAD4 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 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 SMAD4-related disorders in the literature, and has been reported in unaffected individuals (PMID: 30267214, 32459922). This variant has been identified in 5/251480 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;C4707243:Familial thoracic aortic aneurysm and aortic dissection Benign:1
Nov 01, 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. -

Juvenile polyposis syndrome Benign:1
Jan 23, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.081
BayesDel_addAF
Uncertain
0.13
D
BayesDel_noAF
Uncertain
0.030
CADD
Uncertain
25
DANN
Benign
0.96
DEOGEN2
Uncertain
0.56
D;D
Eigen
Benign
0.14
Eigen_PC
Uncertain
0.28
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.89
.;D
M_CAP
Uncertain
0.27
D
MetaRNN
Uncertain
0.50
D;D
MetaSVM
Uncertain
0.44
D
MutationAssessor
Benign
0.90
L;L
PhyloP100
3.6
PrimateAI
Uncertain
0.70
T
PROVEAN
Benign
-1.4
N;N
REVEL
Uncertain
0.53
Sift
Benign
0.36
T;T
Sift4G
Benign
0.21
T;T
Polyphen
0.67
P;P
Vest4
0.56
MVP
0.86
MPC
0.47
ClinPred
0.18
T
GERP RS
5.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.29
gMVP
0.24
Mutation Taster
=68/32
polymorphism

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

Other links and lift over

dbSNP: rs370176106; hg19: chr18-48584806; COSMIC: COSV61687962; COSMIC: COSV61687962; API