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
Consequence
NM_000312.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -6 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
PROC | NM_000312.4 | c.565C>T | p.Arg189Trp | missense_variant | 7/9 | ENST00000234071.8 | |
LOC105373608 | XR_007087228.1 | n.3191G>A | non_coding_transcript_exon_variant | 2/2 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
PROC | ENST00000234071.8 | c.565C>T | p.Arg189Trp | missense_variant | 7/9 | 1 | NM_000312.4 | P1 |
Frequencies
GnomAD3 genomes AF: 0.000467 AC: 71AN: 152094Hom.: 1 Cov.: 32
GnomAD3 exomes AF: 0.000752 AC: 189AN: 251346Hom.: 2 AF XY: 0.000751 AC XY: 102AN XY: 135888
GnomAD4 exome AF: 0.000208 AC: 304AN: 1461792Hom.: 2 Cov.: 31 AF XY: 0.000220 AC XY: 160AN XY: 727190
GnomAD4 genome AF: 0.000460 AC: 70AN: 152212Hom.: 1 Cov.: 32 AF XY: 0.000497 AC XY: 37AN XY: 74414
ClinVar
Submissions by phenotype
Thrombophilia due to protein C deficiency, autosomal dominant Pathogenic:2Uncertain:3
Uncertain significance, criteria provided, single submitter | clinical testing | Mendelics | May 28, 2019 | - - |
Uncertain significance, criteria provided, single submitter | research | CSER _CC_NCGL, University of Washington | Jun 01, 2014 | Low GERP score may suggest that this variant may belong in a lower pathogenicity class - |
Pathogenic, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Apr 27, 2017 | The 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 submitter | clinical testing | Labcorp Genetics (formerly Invitae), Labcorp | Aug 10, 2022 | This 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 submitter | clinical testing | Genetics and Molecular Pathology, SA Pathology | Dec 17, 2019 | - - |
Reduced protein C activity Pathogenic:1
Likely pathogenic, criteria provided, single submitter | research | NIHR Bioresource Rare Diseases, University of Cambridge | Feb 01, 2019 | - - |
Thrombophilia 3 due to protein C deficiency Pathogenic:1
Established risk allele, no assertion criteria provided | research | Department 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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at