chr19-50403580-C-T
Variant summary
Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong
The NM_002691.4(POLD1):c.1225C>T(p.Arg409Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,459,638 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R409G) has been classified as Uncertain significance.
Frequency
Consequence
NM_002691.4 missense
Scores
Clinical Significance
Conservation
Publications
- POLD1-related polyposis and colorectal cancer syndromeInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- colorectal cancer, susceptibility to, 10Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
- mandibular hypoplasia-deafness-progeroid syndromeInheritance: AD, AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Genomics England PanelApp, Ambry Genetics, Orphanet, G2P
- Polymerase proofreading-related adenomatous polyposisInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- immunodeficiency 120Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
- non-severe combined immunodeficiency due to polymerase delta deficiencyInheritance: AR Classification: LIMITED Submitted by: ClinGen
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 6 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| POLD1 | NM_002691.4 | c.1225C>T | p.Arg409Trp | missense_variant | Exon 10 of 27 | ENST00000440232.7 | NP_002682.2 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251404 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000274 AC: 4AN: 1459638Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3AN XY: 726288 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Colorectal cancer, susceptibility to, 10 Uncertain:4
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This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 409 of the POLD1 protein (p.Arg409Trp). This variant is present in population databases (rs778135510, gnomAD 0.003%). This missense change has been observed in individual(s) with early onset colorectal cancer and polyposis (PMID: 26133394). ClinVar contains an entry for this variant (Variation ID: 486071). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt POLD1 protein function with a positive predictive value of 80%. 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. -
Hereditary cancer-predisposing syndrome Uncertain:2
PM2_supporting c.1225C>T, located in exon 10 of the POLD1 gene, is predicted to result in the substitution of Arginine by Tryptophan at codon 409, p.(Arg409Trp). This variant is found in 1/236874 alleles at a frequency of 0.0004% in the gnomAD v2.1.1 database, non-cancer dataset (PM2_supporting). The SpliceAI algorithm predicts no significant impact on splicing and the REVEL meta-predictor score (0.44) for this variant is indeterminate regarding the effect that it may have on protein function according Pejaver 2022 thresholds (PMID: 36413997). To our knowledge, well-stablished functional studies have not been reported for this variant. It has been identified in individuals affected with colorectal cancer (internal data, Bellido 2016). Based on currently available information, c.1225C>T is classified as an uncertain significance variant according to POLD1 guidelines. Comments: variant reclassificada per IMPaCT. -
The p.R409W variant (also known as c.1225C>T), located in coding exon 9 of the POLD1 gene, results from a C to T substitution at nucleotide position 1225. The arginine at codon 409 is replaced by tryptophan, an amino acid with dissimilar properties. This alteration was identified in an individual with microsatellite-stable colorectal cancer diagnosed at 32 (Bellido F et al. Genet. Med., 2016 Apr;18:325-32). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Identified in patients with colorectal cancer and/or polyps (Bellido et al., 2016; Georgeson et al., 2022); This variant is associated with the following publications: (PMID: 20951805, 35668106, 34897210, 26133394) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at