rs16952790

chr18-51068528-A-G

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 0P and 12B. BP4_Strong BA1

The NM_005359.6(SMAD4):c.1308+1341A>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0467 in 152,288 control chromosomes in the GnomAD database, including 581 homozygotes. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.047 (581 hom., cov: 32)
• Consequence: SMAD4 NM_005359.6 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.729

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]

ACMG classification

Verdict is Benign. Variant got -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.88).
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.155 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMAD4	NM_005359.6	c.1308+1341A>G		intron_variant		ENST00000342988.8
SMAD4	NM_001407041.1	c.1308+1341A>G		intron_variant
SMAD4	NM_001407042.1	c.1308+1341A>G		intron_variant
SMAD4	NR_176265.1	n.1846+1341A>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMAD4	ENST00000342988.8	c.1308+1341A>G		intron_variant		5	NM_005359.6	P1

Frequencies

GnomAD3 genomes AF: 0.0465 AC: 7083 AN: 152170 Hom.: 577 Cov.: 32

Gnomad AFR AF: 0.158

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0209

Gnomad ASJ AF: 0.00259

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.0127

Gnomad NFE AF: 0.00163

Gnomad OTH AF: 0.0445

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

GnomAD4 genome AF: 0.0467 AC: 7118 AN: 152288 Hom.: 581 Cov.: 32 AF XY: 0.0454 AC XY: 3382 AN XY: 74476

Gnomad4 AFR AF: 0.158

Gnomad4 AMR AF: 0.0209

Gnomad4 ASJ AF: 0.00259

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00163

Gnomad4 OTH AF: 0.0440

Alfa AF: 0.0303 Hom.: 52

Bravo AF: 0.0537

Asia WGS AF: 0.0180 AC: 62 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.88
Cadd	Benign	5.4
Dann	Benign	0.52

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: rs16952790; hg19: chr18-48594898;