rs121909554

Variant names:

• chr1-173904011-G-A
• rs121909554
• NM_000488.4:c.1273C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM2_Supporting PP3 PP4 PS4 PP1_Moderate PM5

This summary comes from the ClinGen Evidence Repository: The c.1273C>T variant in SERPINC1 is a missense variant predicted to cause substitution of arginine by cysteine at amino acid 425 (p.Arg425Cys). This variant is seen with a total MAF of 0.0000006195, which meets PM2_Supporting. At least one patient with this variant displayed an antithrombin activity level of < 0.8 IU/mL on repeated independent samples, which is highly specific for hereditary antithrombin deficiency (PP4, PMID:27098529). This variant has been reported in eight more probands with an antithrombin activity level of < 0.8 IU/mL, but not all of them had testing performed on repeated independent samples, crossed immunoelectrophoresis demonstrating an abnormal result or a family history (5.5 points awarded, PS4; PMIDs:22398878, 28300866, 23910795, 4049307, 22481271, 27098529). The variant has been reported to segregate with hereditary antithrombin deficiency in four affected family members, aside from the proband, from one family (PP1_Moderate; PMID:4049307). Another missense variant c.1274G>A (p.Arg425His) (ClinVarID:18019) in the same codon has been classified as pathogenic for hereditary antithrombin deficiency by the ClinGen Thrombosis VCEP (PM5). The computational predictor REVEL gives a score of 0.806, which is above the threshold of 0.6, evidence that correlates with impact to SERPINC1 function (PP3). In summary, this variant meets the criteria to be classified as pathogenic for autosomal dominant hereditary antithrombin deficiency based on the ACMG/AMP criteria applied, as specified by the ClinGen Thrombosis VCEP: PS4, PP1_Moderate, PM5, PM2_Supporting, PP3, PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA210762/MONDO:0013144/084

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: SERPINC1 NM_000488.4 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:4
• Conservation: PhyloP100: 7.20
• Publications: 6 publications found

Genes affected

SERPINC1 (HGNC:775): (serpin family C member 1) The protein encoded by this gene, antithrombin III, is a plasma protease inhibitor and a member of the serpin superfamily. This protein inhibits thrombin as well as other activated serine proteases of the coagulation system, and it regulates the blood coagulation cascade. The protein includes two functional domains: the heparin binding-domain at the N-terminus of the mature protein, and the reactive site domain at the C-terminus. The inhibitory activity is enhanced by the presence of heparin. Numerous mutations have been identified for this gene, many of which are known to cause antithrombin-III deficiency which constitutes a strong risk factor for thrombosis. A reduction in the serum level of this protein is associated with severe cases of Coronavirus Disease 19 (COVID-19). [provided by RefSeq, Sep 2020]

SERPINC1 Gene-Disease associations (from GenCC):

• hereditary antithrombin deficiency

  Inheritance: AD, AR, SD Classification: DEFINITIVE, STRONG, SUPPORTIVE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), PanelApp Australia, Genomics England PanelApp, Orphanet, ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM5: For more information check the summary or visit ClinGen Evidence Repository.
• PP1: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000488.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SERPINC1	NM_000488.4	MANE Select	c.1273C>T	p.Arg425Cys	missense	Exon 7 of 7	NP_000479.1	P01008
	SERPINC1	NM_001386302.1		c.1396C>T	p.Arg466Cys	missense	Exon 7 of 7	NP_001373231.1
	SERPINC1	NM_001386303.1		c.1354C>T	p.Arg452Cys	missense	Exon 8 of 8	NP_001373232.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SERPINC1	ENST00000367698.4	TSL:1 MANE Select	c.1273C>T	p.Arg425Cys	missense	Exon 7 of 7	ENSP00000356671.3	P01008
	SERPINC1	ENST00000874328.1		c.1402C>T	p.Arg468Cys	missense	Exon 7 of 7	ENSP00000544387.1
	SERPINC1	ENST00000874324.1		c.1396C>T	p.Arg466Cys	missense	Exon 7 of 7	ENSP00000544383.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152168 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251344 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152286 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74458

African (AFR) AF: 0.00 AC: 0 AN: 41562

American (AMR) AF: 0.00 AC: 0 AN: 15304

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10602

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68022

Other (OTH) AF: 0.00 AC: 0 AN: 2110

Alfa AF: 0.00000446 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
4	-	-	Hereditary antithrombin deficiency (4)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.40
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Pathogenic	0.29
CADD	Pathogenic	31
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.83	D
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.92	D
M_CAP	Uncertain	0.10	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Uncertain	0.52	D
MutationAssessor	Uncertain	2.3	M
PhyloP100		7.2
PrimateAI	Uncertain	0.55	T
PROVEAN	Uncertain	-3.8	D
REVEL	Pathogenic	0.86
Sift	Benign	0.27	T
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.96
MVP		0.92
MPC		1.3
ClinPred		0.98	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.88
gMVP		0.91
Mutation Taster		=6/94	disease causing (ClinVar)

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: rs121909554; hg19: chr1-173873149;