NM_004153.4:c.2013G>C

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_004153.4(ORC1):c.2013G>C(p.Leu671Leu) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.0000434 in 1,612,280 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000045 ( 0 hom. )

Consequence

ORC1
NM_004153.4 splice_region, synonymous

Scores

Splicing: ADA: 1.000

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 5.58

Variant links:

Genes affected

ORC1 (HGNC:8487): (origin recognition complex subunit 1) The origin recognition complex (ORC) is a highly conserved six subunits protein complex essential for the initiation of the DNA replication in eukaryotic cells. Studies in yeast demonstrated that ORC binds specifically to origins of replication and serves as a platform for the assembly of additional initiation factors such as Cdc6 and Mcm proteins. The protein encoded by this gene is the largest subunit of the ORC complex. While other ORC subunits are stable throughout the cell cycle, the levels of this protein vary during the cell cycle, which has been shown to be controlled by ubiquitin-mediated proteolysis after initiation of DNA replication. This protein is found to be selectively phosphorylated during mitosis. It is also reported to interact with MYST histone acetyltransferase 2 (MyST2/HBO1), a protein involved in control of transcription silencing. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2010]

ORC1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ORC1	NM_004153.4 link	c.2013G>C	p.Leu671Leu	splice_region_variant, synonymous_variant	Exon 13 of 17	ENST00000371568.8	NP_004144.2	Q13415

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ORC1	ENST00000371568.8 link	c.2013G>C	p.Leu671Leu	splice_region_variant, synonymous_variant	Exon 13 of 17	1	NM_004153.4	ENSP00000360623.3		Q13415
ORC1	ENST00000371566.1 link	c.2013G>C	p.Leu671Leu	splice_region_variant, synonymous_variant	Exon 13 of 17	1		ENSP00000360621.1		Q13415

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152192

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000398

AC:

AN:

251414

Hom.:

AF XY:

0.0000442

AC XY:

AN XY:

135880

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000616

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000445

AC:

AN:

1460088

Hom.:

Cov.:

AF XY:

0.0000454

AC XY:

AN XY:

726344

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

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:

0.0000576

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152192

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000564

Hom.:

Bravo

AF:

0.0000453

EpiCase

AF:

0.000109

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Sep 02, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects codon 671 of the ORC1 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the ORC1 protein. This variant also falls at the last nucleotide of exon 13, which is part of the consensus splice site for this exon. This variant is present in population databases (rs140536267, ExAC 0.01%). This variant has been observed in individual(s) with clinical features of ORC1-related conditions (Invitae). ClinVar contains an entry for this variant (Variation ID: 445650). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). 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. -

Apr 28, 2017

Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases

Pathogenic:1

Jan 31, 2025

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2013G>C (p.L671L) alteration is located in exon 13 (coding exon 12) of the ORC1 gene. This alteration consists of a G to C substitution at nucleotide position 2013. This nucleotide substitution does not change the leucine at codon 671. However, this change occurs in the last base pair of coding exon 12, which makes it likely to have some effect on normal mRNA splicing. Based on data from gnomAD, the C allele has an overall frequency of 0.004% (11/282816) total alleles studied. The highest observed frequency was 0.012% (3/24972) of African alleles. This variant was reported in conjunction with another ORC1 variant in individuals with features consistent with consistent with ORC1-related Meier-Gorlin syndrome (Ambry internal data; external communication). This nucleotide position is highly conserved in available vertebrate species. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). In silico splice site analysis for this alteration is inconclusive. Based on the available evidence, this alteration is classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.34

CADD

Benign

DANN

Benign

0.93

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.98

SpliceAI score (max)

0.19

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over