chr2-127426114-C-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 2P and 8B. PM1BP4_StrongBS2

The NM_000312.4(PROC):​c.565C>T​(p.Arg189Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000232 in 1,614,004 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R189Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00046 ( 1 hom., cov: 32)
Exomes 𝑓: 0.00021 ( 2 hom. )

Consequence

PROC
NM_000312.4 missense

Scores

1
3
14

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:3

Conservation

PhyloP100: -0.0360
Variant links:
Genes affected
PROC (HGNC:9451): (protein C, inactivator of coagulation factors Va and VIIIa) This gene encodes a vitamin K-dependent plasma glycoprotein. The encoded protein is cleaved to its activated form by the thrombin-thrombomodulin complex. This activated form contains a serine protease domain and functions in degradation of the activated forms of coagulation factors V and VIII. Mutations in this gene have been associated with thrombophilia due to protein C deficiency, neonatal purpura fulminans, and recurrent venous thrombosis.[provided by RefSeq, Dec 2009]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000312.4
BP4
Computational evidence support a benign effect (MetaRNN=0.0060937107).
BS2
High Homozygotes in GnomAdExome4 at 2 SD gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
PROCNM_000312.4 linkuse as main transcriptc.565C>T p.Arg189Trp missense_variant 7/9 ENST00000234071.8
LOC105373608XR_007087228.1 linkuse as main transcriptn.3191G>A non_coding_transcript_exon_variant 2/2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
PROCENST00000234071.8 linkuse as main transcriptc.565C>T p.Arg189Trp missense_variant 7/91 NM_000312.4 P1P04070-1

Frequencies

GnomAD3 genomes
AF:
0.000467
AC:
71
AN:
152094
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000193
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00905
Gnomad SAS
AF:
0.00207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000588
Gnomad OTH
AF:
0.000479
GnomAD3 exomes
AF:
0.000752
AC:
189
AN:
251346
Hom.:
2
AF XY:
0.000751
AC XY:
102
AN XY:
135888
show subpopulations
Gnomad AFR exome
AF:
0.000246
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00805
Gnomad SAS exome
AF:
0.000686
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000114
Gnomad OTH exome
AF:
0.000326
GnomAD4 exome
AF:
0.000208
AC:
304
AN:
1461792
Hom.:
2
Cov.:
31
AF XY:
0.000220
AC XY:
160
AN XY:
727190
show subpopulations
Gnomad4 AFR exome
AF:
0.0000597
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00390
Gnomad4 SAS exome
AF:
0.000661
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000306
Gnomad4 OTH exome
AF:
0.000894
GnomAD4 genome
AF:
0.000460
AC:
70
AN:
152212
Hom.:
1
Cov.:
32
AF XY:
0.000497
AC XY:
37
AN XY:
74414
show subpopulations
Gnomad4 AFR
AF:
0.000193
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00888
Gnomad4 SAS
AF:
0.00207
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000588
Gnomad4 OTH
AF:
0.000474
Alfa
AF:
0.000219
Hom.:
1
Bravo
AF:
0.000264
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.000717
AC:
87
Asia WGS
AF:
0.00837
AC:
29
AN:
3478
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:4Uncertain:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Thrombophilia due to protein C deficiency, autosomal dominant Pathogenic:2Uncertain:3
Uncertain significance, criteria provided, single submitterclinical testingMendelicsMay 28, 2019- -
Uncertain significance, criteria provided, single submitterresearchCSER _CC_NCGL, University of WashingtonJun 01, 2014Low GERP score may suggest that this variant may belong in a lower pathogenicity class -
Pathogenic, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaApr 27, 2017The PROC c.565C>T (p.Arg189Trp) variant is reported as a cause of type II protein C deficiency that produces a protein with decreased functional activity and a relatively normal antigen level. Heterozygous carriers of pathogenic variants in the PROC gene are said to have mild protein C deficiency which is often asymptomatic, but may involve recurrent venous thrombosis. Tang et al. (2012) identified the p.Arg189Trp variant in 17 of 36 individuals diagnosed with hereditary protein C deficiency. All 17 individuals were heterozygous for the variant, had repeated low plasma protein C activity, and a clinical history of deep vein thrombosis (DVT). The authors then evaluated the p.Arg189Trp variant in a case-control study and found the variant in 59 of 1003 individuals with venous thrombosis. The authors conclude that the p.Arg189Trp variant is the most frequent pathogenic variant associated with protein C deficiency in the Chinese population and a significant risk factor for venous thrombosis. The p.Arg189Trp variant has also been reported in more recent study in which it is found in one individual in a compound heterozygous state (Kim et al. 2014). The p.Arg189Trp variant is reported in a heterozygous state in nine out of 4031 controls and at a frequency of 0.01984 in the East Asian population of the Exome Aggregation Consortium including two homozygotes. This allele frequency is high but is consistent with the disease prevalence. Based on the evidence from the literature, the p.Arg189Trp variant is classified as pathogenic for protein C deficiency. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpAug 10, 2022This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 189 of the PROC protein (p.Arg189Trp). This variant is present in population databases (rs146922325, gnomAD 0.7%), including at least one homozygous and/or hemizygous individual. This missense change has been observed in individual(s) with venous thromboembolism and PROC-deficiency (PMID: 7482420, 22545135, 22817391, 22944127, 23332921, 24028705, 24162787, 28111891, 32717757). ClinVar contains an entry for this variant (Variation ID: 161342). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. Experimental studies have shown that this missense change affects PROC function (PMID: 23389250). 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. -
Likely pathogenic, criteria provided, single submitterclinical testingGenetics and Molecular Pathology, SA PathologyDec 17, 2019- -
Reduced protein C activity Pathogenic:1
Likely pathogenic, criteria provided, single submitterresearchNIHR Bioresource Rare Diseases, University of CambridgeFeb 01, 2019- -
Thrombophilia 3 due to protein C deficiency Pathogenic:1
Established risk allele, no assertion criteria providedresearchDepartment of Pathology and Laboratory Medicine, Sinai Health System-The PROC c.565C>T (p.Arg189Trp) (also known as the p.Arg147Trp variant in the literature) has been identified as a common variant causing protein C deficiency among East Asian populations, with a reported frequency of 27.8% in the protein C deficient Chinese population (Ding_2014_PMID:23389250). The variant has been identified in numerous homozygous and heterozygous individuals with deep vein thrombosis (DVT) and protein C deficiency (Duc Do_2021_PMID:32964666, Tang_2012_PMID:22545135, Li_2018_PMID:30210609, Ding_2014_PMID:23389250, Tang_2012_PMID:22817391). One case-control study in a Chinese DVT patient population identified the p.Arg189Trp variant at a frequency of 5.88% in the DVT population compared to 0.87% in healthy controls, and identified that first-degree relatives of affected patients who harbour the p.R189W variant have an 8.8-fold increased risk of venous thrombosis (Tang_2012_PMID:22817391, Tang_2012_PMID:22545135). The variant was identified in dbSNP (ID: rs146922325) and ClinVar (classified as uncertain by Invitae, Mendelics and 1 other submitter, pathogenic by Illumina, and likely pathogenic by NIHR Bioresource Rare Diseases, University of Cambridge). The variant was identified in control databases in 202 of 282736 chromosomes (2 homozygous) at a frequency of 0.0007144, and was observed at the highest frequency in the East Asian population in 156 of 19950 chromosomes (freq: 0.007820) (Genome Aggregation Database March 6, 2019, v2.1.1). The p.Arg189 residue is conserved in mammals and computational analyses (MUT Assesor, PolyPhen-2, SIFT, MutationTaster, Revel, FATHMM, MetaLR) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (Splice AI) predict an uncertain effect on splicing. The p.Arg189Trp variant has shown to exhibit ~3 fold lower affinity for binding the EPCR transmembrane receptor (Ding_2014_PMID:23389250). In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time although we would lean towards a more pathogenic role for this variant. This variant is classified as likely pathogenic – risk factor for thrombophilia due to protein C deficiency. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.095
BayesDel_addAF
Benign
-0.14
T
BayesDel_noAF
Uncertain
0.030
CADD
Benign
14
DANN
Benign
0.95
DEOGEN2
Uncertain
0.64
D;.;.
Eigen
Benign
-0.93
Eigen_PC
Benign
-1.0
FATHMM_MKL
Benign
0.14
N
LIST_S2
Benign
0.72
T;T;T
MetaRNN
Benign
0.0061
T;T;T
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Benign
1.5
L;.;.
MutationTaster
Benign
1.0
N;N;N;N
PrimateAI
Benign
0.33
T
PROVEAN
Benign
-2.1
N;D;N
REVEL
Uncertain
0.58
Sift
Benign
0.10
.;T;.
Sift4G
Benign
0.064
T;T;T
Polyphen
0.18
B;.;B
Vest4
0.12
MVP
0.91
MPC
0.47
ClinPred
0.0091
T
GERP RS
-0.86
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.24
gMVP
0.81

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.13
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.

Other links and lift over

dbSNP: rs146922325; hg19: chr2-128183690; COSMIC: COSV52167078; COSMIC: COSV52167078; API