18-51078455-A-G

Variant names:

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_005359.6(SMAD4):c.1647A>G(p.Gln549Gln) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000366 in 1,613,484 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000034 ( 0 hom. )

Consequence

SMAD4
NM_005359.6 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:11

Conservation

PhyloP100: -0.730

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.52).

BP6

Variant 18-51078455-A-G is Benign according to our data. Variant chr18-51078455-A-G is described in ClinVar as [Likely_benign]. Clinvar id is 231980.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr18-51078455-A-G is described in Lovd as [Likely_benign].

BP7

Synonymous conserved (PhyloP=-0.73 with no splicing effect.

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0000657 (10/152278) while in subpopulation AFR AF= 0.00012 (5/41562). AF 95% confidence interval is 0.0000473. 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 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMAD4	NM_005359.6 link	c.1647A>G	p.Gln549Gln	synonymous_variant	Exon 12 of 12	ENST00000342988.8	NP_005350.1	Q13485A0A024R274
SMAD4	NM_001407041.1 link	c.1647A>G	p.Gln549Gln	synonymous_variant	Exon 12 of 12		NP_001393970.1
SMAD4	NM_001407042.1 link	c.1647A>G	p.Gln549Gln	synonymous_variant	Exon 12 of 12		NP_001393971.1
SMAD4	NR_176265.1 link	n.2298A>G		non_coding_transcript_exon_variant	Exon 13 of 13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMAD4	ENST00000342988.8 link	c.1647A>G	p.Gln549Gln	synonymous_variant	Exon 12 of 12	5	NM_005359.6	ENSP00000341551.3		Q13485

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152160

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000279

AC:

AN:

250984

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135626

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.0000579

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000335

AC:

AN:

1461206

Hom.:

Cov.:

AF XY:

0.0000303

AC XY:

AN XY:

726910

show subpopulations

Gnomad4 AFR exome

AF:

0.000179

Gnomad4 AMR exome

AF:

0.0000895

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000180

Gnomad4 OTH exome

AF:

0.000232

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152278

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.000120

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.000288

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000677

Hom.:

Bravo

AF:

0.0000680

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:11

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:5

Jun 21, 2017

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 25, 2017

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The SMAD4 c.1647A>G;p.Gln549Gln variant is listed as likely benign in the ClinVar database (Variation ID: 231980). The variant is listed in the dbSNP variant database (rs113545983) with an allele frequency of 0.0154 percent (2/13004 alleles) in the Exome Variant Server and 0.002849 percent (7/245724 alleles) in the Genome Aggregation Database. The nucleotide at this position is weakly conserved across species and computational algorithms (SpliceSiteFinder-like, MaxEntScan, NNSplice, GeneSplicer, Human Splicing Finder) predict this variant will not alter splicing. One publication indicated that this variant may be associated with poor prognosis in pancreatic cancer, but is not necessarily causative for cancer (Javle 2014). Considering available information, this variant is classified as likely benign. References: Javle M et al. Biomarkers of TGF-ÃŸ signaling pathway and prognosis of pancreatic cancer. PLoS One. 2014 Jan 20;9(1):e85942. -

Jun 26, 2017

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The c.1647A>G (p.Gln549=) in SMAD4 gene is a synonymous change that involves a non-conserved nucleotide. 4/5 programs in Alamut predict that this variant does not affect the normal splicing, however no functional studies supporting this notion were published at the time of evaluation. The variant is present in the control population datasets of ExAC and gnomAD at a similar frequencies 0.000028 (3/120978 and 7/245724 chrs tested, respectively). However, the possibility of the variant to be derived from pseudogene cannot be completely ruled out. The variant has not, to our knowledge, been reported in affected individuals via published reports but is cited as Benign/Likely Benign by reputable databases/clinical laboratories. Taking together, the variant was classified as Benign. -

Nov 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

SMAD4: BP4, BP7 -

Nov 17, 2017

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome

Benign:2

Aug 31, 2020

Sema4, Sema4

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: curation

- -

Oct 09, 2016

Color Diagnostics, LLC DBA Color Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Benign:1

Jul 31, 2015

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Hereditary cancer-predisposing syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection

Benign:1

Jun 02, 2015

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/hereditary hemorrhagic telangiectasia syndrome

Benign:1

Dec 01, 2023

All of Us Research Program, National Institutes of Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Juvenile polyposis syndrome

Benign:1

Jan 17, 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

BayesDel_noAF

Benign

-0.52

CADD

Benign

0.89

DANN

Benign

0.41

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over