NM_000488.4:c.1322T>C

Variant names:

• chr1-173903962-A-G
• rs1188571702
• NM_000488.4:c.1322T>C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PS1_Moderate PM1 PM2 PP3_Strong PP5_Moderate

The NM_000488.4(SERPINC1):​c.1322T>C​(p.Leu441Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in UniProt.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SERPINC1 NM_000488.4 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.52

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PS1: Transcript NM_000488.4 (SERPINC1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt
• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000488.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.986
• PP5: Variant 1-173903962-A-G is Pathogenic according to our data. Variant chr1-173903962-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 3720258.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SERPINC1	NM_000488.4	c.1322T>C	p.Leu441Pro	missense_variant	Exon 7 of 7	ENST00000367698.4	NP_000479.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SERPINC1	ENST00000367698.4	c.1322T>C	p.Leu441Pro	missense_variant	Exon 7 of 7	1	NM_000488.4	ENSP00000356671.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary antithrombin deficiency Pathogenic:1

Jan 21, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 441 of the SERPINC1 protein (p.Leu441Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with antithrombin deficiency (PMID: 12894857, 28300866, 36214221). This variant is also known as 13344T>C, L409P. Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt SERPINC1 protein function with a positive predictive value of 95%. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on SERPINC1 function (PMID: 36214221). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.93	.;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.78	T;D
M_CAP	Pathogenic	0.45	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Pathogenic	4.4	.;H
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-6.1	.;D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	.;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	.;D
Vest4		0.93
MutPred		0.92		.;Loss of stability (P = 0.0145);
MVP		0.94
MPC		1.5
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.99
gMVP		1.0

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

Publications

LitVar

Other links and lift over

dbSNP: rs1188571702; hg19: chr1-173873100;