rs377119288

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 1P and 11B. PP2BP4_ModerateBP6BS1BS2

The NM_005359.6(SMAD4):​c.947A>G​(p.Asn316Ser) variant causes a missense change. The variant allele was found at a frequency of 0.0000434 in 1,611,112 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/21 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 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000044 ( 2 hom. )

Consequence

SMAD4
NM_005359.6 missense

Scores

1
6
12

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:5O:1

Conservation

PhyloP100: 5.50
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -10 ACMG points.

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=0.24306044).
BP6
Variant 18-51059908-A-G is Benign according to our data. Variant chr18-51059908-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 135245.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Benign=2, Uncertain_significance=6, not_provided=1}.
BS1
Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.0000394 (6/152130) while in subpopulation EAS AF= 0.000385 (2/5198). AF 95% confidence interval is 0.0000681. There are 0 homozygotes in gnomad4. There are 3 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High AC in GnomAd4 at 6 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SMAD4NM_005359.6 linkc.947A>G p.Asn316Ser missense_variant Exon 8 of 12 ENST00000342988.8 NP_005350.1 Q13485A0A024R274

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SMAD4ENST00000342988.8 linkc.947A>G p.Asn316Ser missense_variant Exon 8 of 12 5 NM_005359.6 ENSP00000341551.3 Q13485

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152130
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000385
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.0000557
AC:
14
AN:
251388
Hom.:
0
AF XY:
0.0000810
AC XY:
11
AN XY:
135870
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000109
Gnomad SAS exome
AF:
0.000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000439
AC:
64
AN:
1458982
Hom.:
2
Cov.:
29
AF XY:
0.0000592
AC XY:
43
AN XY:
726098
show subpopulations
Gnomad4 AFR exome
AF:
0.0000599
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000758
Gnomad4 SAS exome
AF:
0.000452
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000126
Gnomad4 OTH exome
AF:
0.0000829
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152130
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74296
show subpopulations
Gnomad4 AFR
AF:
0.0000724
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.000385
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.000478
Alfa
AF:
0.0000772
Hom.:
0
Bravo
AF:
0.0000567
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.0000576
AC:
7
Asia WGS
AF:
0.00144
AC:
5
AN:
3478
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:6Benign:5Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Benign:2Other:1
Jan 16, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: SMAD4 c.947A>G (p.Asn316Ser) results in a conservative amino acid change in 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 5.6e-05 in 251388 control chromosomes, predominantly at a frequency of 0.00033 within the South Asian subpopulation in the gnomAD database. The observed variant frequency within South Asian control individuals in the gnomAD database is approximately 165 fold of the estimated maximal expected allele frequency for a pathogenic variant in SMAD4 causing Juvenile Polyposis Syndrome phenotype (2e-06), strongly suggesting that the variant is a benign polymorphism found primarily in populations of South Asian origin. c.947A>G has been reported in the literature in individuals who underwent multigene panel testing for a variety of indications. As a representative ascertainment, it was reported as a probably benign variant in a patient with medulloblastoma (e.g., Zhang_2015), as a VUS in patients with polyps/colorectal cancer (e.g., Chang_2017, Buendia_2021, Xu_2020), as a VUS in a patient with pulmonary hypertension (e.g., Yang_2018), as a VUS in a patient with breast and/or ovarian cancer (e.g., Kwong_2020). These reports do not provide unequivocal conclusions about association of the variant with Juvenile Polyposis Syndrome. At-least one recent report of co-occurrences with other pathogenic variants has been described in a 15 year old with an early onset colorectal adenocarcinoma who harbored pathogenic germline variants in both the APC and the MLH1 gene (APC c.3329C>A, p.Ser110*; MLH1 c.156del, p.Glu53Argfs*4, Buendia_2021), providing supporting evidence for a benign role. The APC variant was reported as a spontaneous mutation whereas the MLH1 and this SMAD4 variants were both maternally derived. 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: 26580448, 32068069, 33745841, 29069792, 29743074, 32973888). ClinVar contains an entry for this variant (Variation ID: 135245). Based on the evidence outlined above, the variant was classified as likely benign. -

Aug 13, 2024
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Sep 19, 2013
ITMI
Significance: not provided
Review Status: no classification provided
Collection Method: reference population

- -

not provided Uncertain:2
Feb 10, 2017
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 04, 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; This variant is associated with the following publications: (PMID: 31856217, 32068069, 24728327, 28199989, 29069792, 29743074, 32973888, 33745841, 35670754, 29212164, 26580448, 10636916, 37966258, 36243179) -

Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
Mar 09, 2022
Sema4, Sema4
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: curation

- -

Feb 11, 2020
Color Diagnostics, LLC DBA Color Health
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Aug 04, 2017
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Generalized juvenile polyposis/juvenile polyposis coli Uncertain:1
Dec 16, 2015
Counsyl
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome Uncertain:1
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. -

Hereditary cancer-predisposing syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Benign:1
Sep 12, 2022
Ambry Genetics
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This alteration is classified as 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: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.062
BayesDel_addAF
Benign
-0.20
T
BayesDel_noAF
Benign
-0.22
CADD
Benign
22
DANN
Benign
0.94
DEOGEN2
Uncertain
0.51
D;D
Eigen
Benign
-0.17
Eigen_PC
Benign
0.050
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.93
.;D
M_CAP
Uncertain
0.14
D
MetaRNN
Benign
0.24
T;T
MetaSVM
Uncertain
0.35
D
MutationAssessor
Benign
1.5
L;L
PrimateAI
Uncertain
0.67
T
PROVEAN
Benign
-0.83
N;N
REVEL
Uncertain
0.36
Sift
Benign
0.87
T;T
Sift4G
Benign
0.92
T;T
Polyphen
0.0020
B;B
Vest4
0.61
MVP
0.78
MPC
0.36
ClinPred
0.066
T
GERP RS
5.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.21
gMVP
0.37

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

LitVar

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

Other links and lift over

dbSNP: rs377119288; hg19: chr18-48586278; COSMIC: COSV105909583; COSMIC: COSV105909583; API