chr5-112775623-AAAT-A
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Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2
The NM_000038.6(APC):c.423-4_423-2del variant causes a splice region, splice polypyrimidine tract, intron change. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Genomes: not found (cov: 32)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control
Consequence
APC
NM_000038.6 splice_region, splice_polypyrimidine_tract, intron
NM_000038.6 splice_region, splice_polypyrimidine_tract, intron
Scores
Not classified
Clinical Significance
Conservation
PhyloP100: 4.78
Genes affected
APC (HGNC:583): (APC regulator of WNT signaling pathway) This gene encodes a tumor suppressor protein that acts as an antagonist of the Wnt signaling pathway. It is also involved in other processes including cell migration and adhesion, transcriptional activation, and apoptosis. Defects in this gene cause familial adenomatous polyposis (FAP), an autosomal dominant pre-malignant disease that usually progresses to malignancy. Mutations in the APC gene have been found to occur in most colorectal cancers, where disease-associated mutations tend to be clustered in a small region designated the mutation cluster region (MCR) and result in a truncated protein product. [provided by RefSeq, Jun 2022]
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ACMG classification
Classification made for transcript
Verdict is Uncertain_significance. Variant got 2 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
APC | NM_000038.6 | c.423-4_423-2del | splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant | ENST00000257430.9 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
APC | ENST00000257430.9 | c.423-4_423-2del | splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant | 5 | NM_000038.6 | P1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 genomes
Cov.:
32
GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0AN: 1429670Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 712388
GnomAD4 exome
Data not reliable, filtered out with message: AC0
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712388
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GnomAD4 genome Cov.: 32
GnomAD4 genome
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32
ClinVar
Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Invitae | Nov 07, 2023 | This sequence change falls in intron 4 of the APC gene. It does not directly change the encoded amino acid sequence of the APC protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or disrupted protein product. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with APC-related conditions (PMID: 25676610). ClinVar contains an entry for this variant (Variation ID: 411534). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 5 and introduces a premature termination codon (PMID: 25676610). The resulting mRNA is expected to undergo nonsense-mediated decay. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. - |
not provided Uncertain:1
Uncertain significance, no assertion criteria provided | literature only | OMIM | May 01, 2015 | - - |
Hereditary cancer-predisposing syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Ambry Genetics | Mar 23, 2023 | The c.423-4_423-2delATA intronic variant, located in intron 3 of the APC gene, results from a deletion of 3 nucleotides within intron 3 of the APC gene. This alteration has been reported in the literature in a family affected with Cenani-Lenz syndrome (Patel N et al. J Med Genet, 2015 May;52:317-21; Maddirevula S et al. Genet Med, 2018 Dec;20:1609-1616). Although these nucleotides are located near a canonical splice site, the canonical splice acceptor "ag" sequence is preserved. In silico splice site analysis predicts that this alteration will not have any significant effect on splicing. RNA studies have demonstrated that this alteration results in an incomplete splice defect; the clinical impact of this abnormal splicing is unknown at this time (Ambry internal data; Patel N et al. J Med Genet, 2015 May;52:317-21; Maddirevula S et al. Genome Biol, 2020 Jun;21:145). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. - |
Computational scores
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SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at