18-51030886-G-C

Position:

• chr18-51030886-G-C

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_Strong BP6 BS1 BS2

The NM_005359.6(SMAD4):​c.-128+263G>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00488 in 151,786 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (no stars).

• Frequency: Genomes: 𝑓 0.0049 (1 hom., cov: 31)
• Consequence: SMAD4 NM_005359.6 intron
• Clinical Significance: Likely benign no assertion criteria provided B:1
• Conservation: PhyloP100: 0.439

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]

ENSG00000267699 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -13 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.68).
• BP6: Variant 18-51030886-G-C is Benign according to our data. Variant chr18-51030886-G-C is described in ClinVar as [Likely_benign]. Clinvar id is 224021.Status of the report is no_assertion_criteria_provided, 0 stars.
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00488 (741/151786) while in subpopulation NFE AF= 0.00774 (525/67822). AF 95% confidence interval is 0.00719. There are 1 homozygotes in gnomad4. There are 350 alleles in male gnomad4 subpopulation. Median coverage is 31. This position pass quality control queck.
• BS2: High AC in GnomAd4 at 741 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMAD4	NM_005359.6	c.-128+263G>C		intron_variant		ENST00000342988.8	NP_005350.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMAD4	ENST00000342988.8	c.-128+263G>C		intron_variant		5	NM_005359.6	ENSP00000341551.3
ENSG00000267699	ENST00000590722.2	n.158-16034G>C		intron_variant		2		ENSP00000465737.1

Frequencies

GnomAD3 genomes AF: 0.00490 AC: 743 AN: 151668 Hom.: 1 Cov.: 31

Gnomad AFR AF: 0.000968

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00308

Gnomad ASJ AF: 0.00838

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00843

Gnomad MID AF: 0.00633

Gnomad NFE AF: 0.00774

Gnomad OTH AF: 0.00480

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.00488 AC: 741 AN: 151786 Hom.: 1 Cov.: 31 AF XY: 0.00472 AC XY: 350 AN XY: 74198

Gnomad4 AFR AF: 0.000966

Gnomad4 AMR AF: 0.00301

Gnomad4 ASJ AF: 0.00838

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000208

Gnomad4 FIN AF: 0.00843

Gnomad4 NFE AF: 0.00774

Gnomad4 OTH AF: 0.00475

Alfa AF: 0.00619 Hom.: 0

Bravo AF: 0.00420

Asia WGS AF: 0.00144 AC: 5 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: no assertion criteria provided

Submissions by phenotype

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, no assertion criteria provided

clinical testing

University of Washington Department of Laboratory Medicine, University of Washington

Dec 01, 2015

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.68
CADD	Benign	15
DANN	Benign	0.83

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

Other links and lift over

dbSNP: rs149534722; hg19: chr18-48557256;