5-177403525-C-T

Position:

• chr5-177403525-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000505.4(F12):​c.1343G>A​(p.Arg448His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000189 in 1,586,612 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign 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. R448C) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: F12 NM_000505.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.19

Genes affected

F12 (HGNC:3530): (coagulation factor XII) This gene encodes coagulation factor XII which circulates in blood as a zymogen. This single chain zymogen is converted to a two-chain serine protease with an heavy chain (alpha-factor XIIa) and a light chain. The heavy chain contains two fibronectin-type domains, two epidermal growth factor (EGF)-like domains, a kringle domain and a proline-rich domain, whereas the light chain contains only a catalytic domain. On activation, further cleavages takes place in the heavy chain, resulting in the production of beta-factor XIIa light chain and the alpha-factor XIIa light chain becomes beta-factor XIIa heavy chain. Prekallikrein is cleaved by factor XII to form kallikrein, which then cleaves factor XII first to alpha-factor XIIa and then to beta-factor XIIa. The active factor XIIa participates in the initiation of blood coagulation, fibrinolysis, and the generation of bradykinin and angiotensin. It activates coagulation factors VII and XI. Defects in this gene do not cause any clinical symptoms and the sole effect is that whole-blood clotting time is prolonged. [provided by RefSeq, Jul 2008]

GRK6 (HGNC:4545): (G protein-coupled receptor kinase 6) This gene encodes a member of the guanine nucleotide-binding protein (G protein)-coupled receptor kinase subfamily of the Ser/Thr protein kinase family. The protein phosphorylates the activated forms of G protein-coupled receptors thus initiating their deactivation. Several transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a disulfide_bond (size 127) in uniprot entity FA12_HUMAN there are 7 pathogenic changes around while only 1 benign (88%) in NM_000505.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.19331667).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
F12	NM_000505.4	c.1343G>A	p.Arg448His	missense_variant	11/14	ENST00000253496.4
F12	XM_011534462.3	c.1007G>A	p.Arg336His	missense_variant	8/11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
F12	ENST00000253496.4	c.1343G>A	p.Arg448His	missense_variant	11/14	1	NM_000505.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000139 AC: 2 AN: 1434280 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 712250

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.07e-7

Gnomad4 OTH exome AF: 0.0000168

GnomAD4 genome AF: 0.00000656 AC: 1 AN: 152332 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74486

Gnomad4 AFR AF: 0.0000240

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 24, 2023

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 448 of the F12 protein (p.Arg448His). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with F12-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt F12 protein function with a negative predictive value of 80%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.072
BayesDel_addAF	Benign	-0.067	T
BayesDel_noAF	Benign	-0.33
CADD	Benign	13
DANN	Uncertain	0.99
DEOGEN2	Benign	0.27	T
Eigen	Benign	-0.73
Eigen_PC	Benign	-0.73
FATHMM_MKL	Benign	0.31	N
LIST_S2	Benign	0.71	T
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.19	T
MetaSVM	Benign	-0.81	T
MutationAssessor	Benign	0.10	N
MutationTaster	Benign	0.93	N
PrimateAI	Benign	0.34	T
PROVEAN	Benign	-1.7	N
REVEL	Uncertain	0.29
Sift	Benign	0.11	T
Sift4G	Benign	0.19	T
Polyphen		0.59	P
Vest4		0.21
MutPred		0.64		Loss of methylation at R448 (P = 0.039);
MVP		0.80
MPC		1.0
ClinPred		0.48	T
GERP RS		-3.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.19
gMVP		0.56

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: rs1483262492; hg19: chr5-176830526;