rs1555687377
Variant summary
Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1PM2PP3_StrongPP5_Very_Strong
The NM_005359.6(SMAD4):c.1309-1G>A variant causes a splice acceptor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Genomes: not found (cov: 32)
Consequence
SMAD4
NM_005359.6 splice_acceptor
NM_005359.6 splice_acceptor
Scores
5
1
1
Splicing: ADA: 1.000
2
Clinical Significance
Conservation
PhyloP100: 9.83
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 Pathogenic. Variant got 22 ACMG points.
PVS1
?
Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.6, offset of 1, new splice context is: aaatgttttttcttaaaaAGtct. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PM2
?
Very rare variant in population databases, with high coverage;
PP3
?
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
?
Variant 18-51076637-G-A is Pathogenic according to our data. Variant chr18-51076637-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 529910.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
SMAD4 | NM_005359.6 | c.1309-1G>A | splice_acceptor_variant | ENST00000342988.8 | |||
SMAD4 | NM_001407041.1 | c.1309-1G>A | splice_acceptor_variant | ||||
SMAD4 | NM_001407042.1 | c.1309-1G>A | splice_acceptor_variant | ||||
SMAD4 | NR_176265.1 | n.1847-1G>A | splice_acceptor_variant, non_coding_transcript_variant |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
SMAD4 | ENST00000342988.8 | c.1309-1G>A | splice_acceptor_variant | 5 | NM_005359.6 | P1 |
Frequencies
GnomAD3 genomes ? Cov.: 32
GnomAD3 genomes
?
Cov.:
32
GnomAD4 exome Cov.: 30
GnomAD4 exome
Cov.:
30
GnomAD4 genome ? Cov.: 32
GnomAD4 genome
?
Cov.:
32
ClinVar
Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link
Submissions by phenotype
Hereditary cancer-predisposing syndrome;C4707243:Familial thoracic aortic aneurysm and aortic dissection Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | Ambry Genetics | Oct 30, 2014 | The c.1309-1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide before coding exon 10 of the SMAD4 gene. In addition, alterations that disrupt the canonical splice acceptor site are typically deleterious in nature (ACMG Recommendations for Standards for Interpretation and Reporting of Sequence Variations. Revision 2007. Genet Med. 2008;10:294). Based on the available evidence, c.1309-1G>A is classified as a pathogenic mutation. - |
Juvenile polyposis syndrome Pathogenic:1
Likely pathogenic, criteria provided, single submitter | clinical testing | Invitae | Nov 16, 2017 | Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in SMAD4 are known to be pathogenic (PMID: 16152648, 16436638, 22810475). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has not been reported in the literature in individuals with SMAD4-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in intron 10 of the SMAD4 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
D
BayesDel_noAF
Pathogenic
Cadd
Pathogenic
Dann
Uncertain
Eigen
Pathogenic
Eigen_PC
Pathogenic
FATHMM_MKL
Pathogenic
D
MutationTaster
Benign
D;D;D
GERP RS
RBP_binding_hub_radar
RBP_regulation_power_radar
Splicing
Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
dbscSNV1_RF
Pathogenic
SpliceAI score (max)
Details are displayed if max score is > 0.2
DS_AG_spliceai
Position offset: 2
DS_AL_spliceai
Position offset: 1
Find out detailed SpliceAI scores and Pangolin per-transcript scores at