rs1337231648

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_002691.4(POLD1):​c.970+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.000000697 in 1,434,000 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Uncertain significance (★★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 7.0e-7 ( 0 hom. )

Consequence

POLD1
NM_002691.4 splice_donor, intron

Scores

5
1
1
Splicing: ADA: 0.9999
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 7.01

Publications

0 publications found
Variant links:
Genes affected
POLD1 (HGNC:9175): (DNA polymerase delta 1, catalytic subunit) This gene encodes the 125-kDa catalytic subunit of DNA polymerase delta. DNA polymerase delta possesses both polymerase and 3' to 5' exonuclease activity and plays a critical role in DNA replication and repair. Alternatively spliced transcript variants have been observed for this gene, and a pseudogene of this gene is located on the long arm of chromosome 6. [provided by RefSeq, Mar 2012]
POLD1 Gene-Disease associations (from GenCC):
  • POLD1-related polyposis and colorectal cancer syndrome
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • colorectal cancer, susceptibility to, 10
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
  • mandibular hypoplasia-deafness-progeroid syndrome
    Inheritance: 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 polyposis
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • immunodeficiency 120
    Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
  • non-severe combined immunodeficiency due to polymerase delta deficiency
    Inheritance: AR Classification: LIMITED Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POLD1NM_002691.4 linkc.970+1G>A splice_donor_variant, intron_variant Intron 8 of 26 ENST00000440232.7 NP_002682.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POLD1ENST00000440232.7 linkc.970+1G>A splice_donor_variant, intron_variant Intron 8 of 26 1 NM_002691.4 ENSP00000406046.1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.97e-7
AC:
1
AN:
1434000
Hom.:
0
Cov.:
34
AF XY:
0.00000141
AC XY:
1
AN XY:
708488
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32948
American (AMR)
AF:
0.00
AC:
0
AN:
43570
Ashkenazi Jewish (ASJ)
AF:
0.0000394
AC:
1
AN:
25386
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39076
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84706
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51760
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4108
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1093564
Other (OTH)
AF:
0.00
AC:
0
AN:
58882
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Colorectal cancer, susceptibility to, 10 Uncertain:1
Oct 09, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects a donor splice site in intron 8 of the POLD1 gene. Missense variants that disrupt the 3'-5' exonuclease (proof-reading) activity of the POLD1 protein are associated with PPAP (polymerase proofreading–associated polyposis) (PMID: 23263490, 23447401). However, loss-of-function variants that result in an absent or severely disrupted POLD1 protein, and missense variants outside the exonuclease domain, are unlikely to be associated with PPAP. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with POLD1-related conditions. ClinVar contains an entry for this variant (Variation ID: 537101). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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:1
Oct 01, 2018
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.970+1G>A intronic variant results from a G to A substitution one nucleotide after coding exon 7 of the POLD1 gene. This nucleotide position is highly conserved in available vertebrate species. Using the BDGP and ESEfinder splice site prediction tools, this alteration is predicted to abolish the native splice donor site; however, direct evidence is unavailable. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. However, loss of function via haploinsufficiency in POLD1 has not been clearly established as a mechanism of disease. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.19
CADD
Pathogenic
32
DANN
Uncertain
0.99
Eigen
Pathogenic
0.97
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Pathogenic
0.99
D
PhyloP100
7.0
GERP RS
3.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=3/97
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.93
SpliceAI score (max)
0.99
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.99
Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs1337231648; hg19: chr19-50905999; API