chr18-51067196-C-T

Variant names:

• chr18-51067196-C-T
• rs1057522058
• NM_005359.6:c.1308+9C>T

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 2P and 12B. PM2 BP4_Strong BP6_Very_Strong

The NM_005359.6(SMAD4):​c.1308+9C>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SMAD4 NM_005359.6 intron
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 0.0620
• Publications: 0 publications found

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

ACMG classification

Our verdict: Benign. The variant received -10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.72).
• BP6: Variant 18-51067196-C-T is Benign according to our data. Variant chr18-51067196-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 1666776.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMAD4	NM_005359.6	c.1308+9C>T		intron_variant	Intron 10 of 11	ENST00000342988.8	NP_005350.1
SMAD4	NM_001407041.1	c.1308+9C>T		intron_variant	Intron 10 of 11		NP_001393970.1
SMAD4	NM_001407042.1	c.1308+9C>T		intron_variant	Intron 10 of 11		NP_001393971.1
SMAD4	NR_176265.1	n.1846+9C>T		intron_variant	Intron 10 of 12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMAD4	ENST00000342988.8	c.1308+9C>T		intron_variant	Intron 10 of 11	5	NM_005359.6	ENSP00000341551.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1342718 Hom.: 0 Cov.: 20 AF XY: 0.00 AC XY: 0 AN XY: 674608

African (AFR) AF: 0.00 AC: 0 AN: 31192

American (AMR) AF: 0.00 AC: 0 AN: 44260

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25314

East Asian (EAS) AF: 0.00 AC: 0 AN: 39086

South Asian (SAS) AF: 0.00 AC: 0 AN: 83496

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52816

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5514

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1004658

Other (OTH) AF: 0.00 AC: 0 AN: 56382

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome Benign:1

Mar 21, 2025

Myriad Genetics, Inc.

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign. This variant is intronic and is not expected to impact mRNA splicing. -

Juvenile polyposis syndrome Benign:1

Dec 23, 2020

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	-0.72
CADD	Benign	10
DANN	Benign	0.70
PhyloP100		0.062
PromoterAI		-0.015	Neutral

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

Other links and lift over

dbSNP: rs1057522058; hg19: chr18-48593566;