3-93900854-C-T

Variant names:

• chr3-93900854-C-T
• rs1553810751
• NM_000313.4:c.677G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_000313.4(PROS1):​c.677G>A​(p.Cys226Tyr) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,734 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. C226S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: PROS1 NM_000313.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.91
• Publications: 0 publications found

Genes affected

PROS1 (HGNC:9456): (protein S) This gene encodes a vitamin K-dependent plasma protein that functions as a cofactor for the anticoagulant protease, activated protein C (APC) to inhibit blood coagulation. It is found in plasma in both a free, functionally active form and also in an inactive form complexed with C4b-binding protein. Mutations in this gene result in autosomal dominant hereditary thrombophilia. An inactive pseudogene of this locus is located at an adjacent region on chromosome 3. Alternative splicing results in multiple transcript variants encoding different isoforms that may undergo similar processing to generate mature protein. [provided by RefSeq, Oct 2015]

PROS1 Gene-Disease associations (from GenCC):

• thrombophilia due to protein S deficiency, autosomal dominant

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• hereditary thrombophilia due to congenital protein S deficiency

  Inheritance: AR, SD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• thrombophilia due to protein S deficiency, autosomal recessive

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 4 uncertain in NM_000313.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 34 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 0.58456 (below the threshold of 3.09). Trascript score misZ: 1.9528 (below the threshold of 3.09). GenCC associations: The gene is linked to thrombophilia due to protein S deficiency, autosomal dominant, thrombophilia due to protein S deficiency, autosomal recessive, hereditary thrombophilia due to congenital protein S deficiency.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PROS1	NM_000313.4	c.677G>A	p.Cys226Tyr	missense_variant	Exon 7 of 15	ENST00000394236.9	NP_000304.2
PROS1	NM_001314077.2	c.773G>A	p.Cys258Tyr	missense_variant	Exon 8 of 16		NP_001301006.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PROS1	ENST00000394236.9	c.677G>A	p.Cys226Tyr	missense_variant	Exon 7 of 15	1	NM_000313.4	ENSP00000377783.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461734 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727174

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53374

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5714

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111974

Other (OTH) AF: 0.00 AC: 0 AN: 60390

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00400497), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Thrombophilia due to protein S deficiency, autosomal recessive Uncertain:1

Jun 03, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine with tyrosine at codon 226 of the PROS1 protein (p.Cys226Tyr). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and tyrosine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with a PROS1-related disease. 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 disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. In summary, this variant has uncertain impact on PROS1 function. The available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;.;.;D;.;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	1.0	.;D;D;D;D;D
M_CAP	Pathogenic	0.41	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Pathogenic	4.6	H;.;.;H;.;.
PhyloP100		5.9
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-8.8	D;.;.;.;.;.
REVEL	Pathogenic	0.98
Sift	Uncertain	0.0020	D;.;.;.;.;.
Sift4G	Pathogenic	0.0	D;.;.;.;.;.
Polyphen		1.0	D;.;.;D;.;.
Vest4		0.94
MutPred		0.99		Loss of disorder (P = 0.0498);.;.;Loss of disorder (P = 0.0498);Loss of disorder (P = 0.0498);.;
MVP		0.99
MPC		0.88
ClinPred		1.0	D
GERP RS		4.1
Varity_R		0.98
gMVP		0.97
Mutation Taster		=7/93	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1553810751; hg19: chr3-93619698;