chr18-51058118-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6

The NM_005359.6(SMAD4):​c.668-7C>T variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,084 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

SMAD4
NM_005359.6 splice_region, splice_polypyrimidine_tract, intron

Scores

2
Splicing: ADA: 0.00005365
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:3

Conservation

PhyloP100: 2.51
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.44).
BP6
Variant 18-51058118-C-T is Benign according to our data. Variant chr18-51058118-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 413441.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Uncertain_significance=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
SMAD4NM_005359.6 linkuse as main transcriptc.668-7C>T splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant ENST00000342988.8

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
SMAD4ENST00000342988.8 linkuse as main transcriptc.668-7C>T splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant 5 NM_005359.6 P1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.85e-7
AC:
1
AN:
1459084
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
725822
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1
Uncertain significance, criteria provided, single submittercurationSema4, Sema4May 14, 2021- -
not provided Benign:1
Likely benign, criteria provided, single submitterclinical testingGeneDxApr 10, 2018This 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. -
Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome Benign:1
Likely benign, criteria provided, single submitterclinical testingAll of Us Research Program, National Institutes of HealthAug 15, 2023- -
Juvenile polyposis syndrome Benign:1
Likely benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpNov 17, 2023- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.44
CADD
Benign
15
DANN
Benign
0.63
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
2.2

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000054
dbscSNV1_RF
Benign
0.0040
SpliceAI score (max)
0.010
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.

Other links and lift over

dbSNP: rs1060504028; hg19: chr18-48584488; API