Genetic Variant SMAD4:p.Ala464Ala (chr18-51076721-C-T) – ACMG Classification: Benign (-19 pts)

Variant summary

Our verdict is Benign. The variant received -19 ACMG points: 0P and 19B. BP4_ModerateBP6_Very_StrongBP7BS1BS2

The NM_005359.6(SMAD4):c.1392C>T(p.Ala464Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000253 in 1,613,072 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 (★★). Synonymous variant affecting the same amino acid position (i.e. A464A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00032 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00025 ( 0 hom. )

Consequence

SMAD4
NM_005359.6 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:18

Conservation

PhyloP100: -2.71

Publications

2 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: ClinGen, PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
Myhre syndrome
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, PanelApp Australia, G2P, Orphanet
generalized juvenile polyposis/juvenile polyposis coli
Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
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

SMAD4 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -19 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.28).

BP6

Variant 18-51076721-C-T is Benign according to our data. Variant chr18-51076721-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 132745.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=-2.71 with no splicing effect.

BS1

Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000315 (48/152256) while in subpopulation AMR AF = 0.00105 (16/15298). AF 95% confidence interval is 0.000656. There are 0 homozygotes in GnomAd4. There are 32 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High AC in GnomAd4 at 48 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005359.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
SMAD4	NM_005359.6	MANE Select	c.1392C>T	p.Ala464Ala	synonymous	Exon 11 of 12	NP_005350.1	Q13485
SMAD4	NM_001407041.1		c.1392C>T	p.Ala464Ala	synonymous	Exon 11 of 12	NP_001393970.1	A0A024R274
SMAD4	NM_001407042.1		c.1392C>T	p.Ala464Ala	synonymous	Exon 11 of 12	NP_001393971.1	Q13485

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
SMAD4	ENST00000342988.8	TSL:5 MANE Select	c.1392C>T	p.Ala464Ala	synonymous	Exon 11 of 12	ENSP00000341551.3	Q13485
SMAD4	ENST00000591126.5	TSL:1	n.3393C>T		non_coding_transcript_exon	Exon 7 of 8
SMAD4	ENST00000714264.1		c.1473C>T	p.Ala491Ala	synonymous	Exon 11 of 12	ENSP00000519545.1	A0AAQ5BHY6

Frequencies

GnomAD3 genomes

AF:

0.000316

AC:

AN:

152138

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000362

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00105

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000206

Gnomad OTH

AF:

0.00144

GnomAD2 exomes

AF:

0.000287

AC:

AN:

251220

AF XY:

0.000236

show subpopulations

Gnomad AFR exome

AF:

0.000246

Gnomad AMR exome

AF:

0.00133

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000150

Gnomad OTH exome

AF:

0.000489

GnomAD4 exome

AF:

0.000246

AC:

360

AN:

1460816

Hom.:

Cov.:

AF XY:

0.000228

AC XY:

166

AN XY:

726740

show subpopulations

African (AFR)

AF:

0.000358

AC:

AN:

33474

American (AMR)

AF:

0.00148

AC:

AN:

44704

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.0000756

AC:

AN:

39678

South Asian (SAS)

AF:

0.0000348

AC:

AN:

86230

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53408

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

0.000230

AC:

255

AN:

1111072

Other (OTH)

AF:

0.000348

AC:

AN:

60354

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.460

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.000315

AC:

AN:

152256

Hom.:

Cov.:

AF XY:

0.000430

AC XY:

AN XY:

74456

show subpopulations

African (AFR)

AF:

0.000361

AC:

AN:

41544

American (AMR)

AF:

0.00105

AC:

AN:

15298

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5170

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10610

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000206

AC:

AN:

68028

Other (OTH)

AF:

0.00142

AC:

AN:

2106

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.516

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000331

Hom.:

Bravo

AF:

0.000450

EpiCase

AF:

0.000109

EpiControl

AF:

0.0000593

ClinVar

ClinVar submissions

Significance:Benign/Likely benign

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (5)

not specified (4)

Hereditary cancer-predisposing syndrome (2)

Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome (2)

Generalized juvenile polyposis/juvenile polyposis coli (1)

Hereditary cancer-predisposing syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection (1)

Juvenile polyposis syndrome (1)

Juvenile polyposis syndrome;C0796081:Myhre syndrome;C1832942:Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome;C2931038:Familial pancreatic carcinoma (1)

Myhre syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.28

CADD

Benign

7.7

(source)

DANN

Benign

0.80

PhyloP100

-2.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=91/9

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over