rs863224732

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6

The NM_005359.6(SMAD4):​c.634G>A​(p.Ala212Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,776 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 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. A212V) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SMAD4
NM_005359.6 missense

Scores

19

Clinical Significance

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

Conservation

PhyloP100: 4.25

Publications

1 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 -1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.08343345).
BP6
Variant 18-51054960-G-A is Benign according to our data. Variant chr18-51054960-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 216603.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMAD4NM_005359.6 linkc.634G>A p.Ala212Thr missense_variant Exon 5 of 12 ENST00000342988.8 NP_005350.1 Q13485A0A024R274

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SMAD4ENST00000342988.8 linkc.634G>A p.Ala212Thr missense_variant Exon 5 of 12 5 NM_005359.6 ENSP00000341551.3 Q13485
ENSG00000267699ENST00000590722.2 linkn.*810G>A non_coding_transcript_exon_variant Exon 8 of 9 2 ENSP00000465737.1 E7EUB6
ENSG00000267699ENST00000590722.2 linkn.*810G>A 3_prime_UTR_variant Exon 8 of 9 2 ENSP00000465737.1 E7EUB6

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251470
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
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:
0.00000137
AC:
2
AN:
1461776
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727190
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000299
AC:
1
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111916
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
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

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:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

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

Submissions by phenotype

Juvenile polyposis syndrome Uncertain:1
Dec 07, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. 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. ClinVar contains an entry for this variant (Variation ID: 216603). This variant has not been reported in the literature in individuals affected with SMAD4-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 212 of the SMAD4 protein (p.Ala212Thr). -

Hereditary cancer-predisposing syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Benign:1
May 12, 2023
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
0.057
BayesDel_addAF
Benign
-0.053
T
BayesDel_noAF
Benign
-0.31
CADD
Benign
15
DANN
Benign
0.90
DEOGEN2
Benign
0.34
T;T;T
Eigen
Benign
-0.61
Eigen_PC
Benign
-0.35
FATHMM_MKL
Benign
0.55
D
LIST_S2
Benign
0.72
.;T;T
M_CAP
Benign
0.055
D
MetaRNN
Benign
0.083
T;T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
-0.90
N;N;.
PhyloP100
4.2
PrimateAI
Benign
0.34
T
PROVEAN
Benign
0.58
N;N;.
REVEL
Benign
0.14
Sift
Benign
0.47
T;T;.
Sift4G
Benign
0.38
T;T;T
Polyphen
0.0
B;B;.
Vest4
0.22
MutPred
0.23
Gain of glycosylation at A212 (P = 8e-04);Gain of glycosylation at A212 (P = 8e-04);Gain of glycosylation at A212 (P = 8e-04);
MVP
0.52
MPC
0.44
ClinPred
0.32
T
GERP RS
3.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.029
gMVP
0.15
Mutation Taster
=86/14
polymorphism

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

Other links and lift over

dbSNP: rs863224732; hg19: chr18-48581330; API