Is F2 p.Phe342= (c.1026C>T) pathogenic?

F2 p.Phe342= (c.1026C>T) is classified Likely benign in F2 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-03-07). Ultra-rare (popmax 0.0165%, mid); Associated with congenital prothrombin deficiency.

What condition is associated with F2 p.Phe342= (c.1026C>T)?

F2 p.Phe342= (c.1026C>T) is associated with congenital prothrombin deficiency (ClinVar).

How common is F2 p.Phe342= (c.1026C>T) in the general population?

F2 p.Phe342= (c.1026C>T) is ultra-rare (popmax 0.0165%, mid) (gnomAD).

How is Congenital factor II deficiency inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

F2 p.Phe342=

c.1026C>T · rs765684282 · VCV2917355

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0165%, mid)

Conditions

congenital prothrombin deficiency

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -6.6	GERP -3.1
Overall
CADD	5.389	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0165% Middle Eastern · 1/6,062 alleles

Filtering AF 0.00225% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00135%

Overall 0.00167% 27/1,614,230 alleles · ultra-rare exomes 27/1,461,870 · genomes 0/152,360 · joint denominator

Ancestry group	Frequency	1 in
Middle Easterngrpmax	0.0165%	6,062
Remaining individualsnot grpmax-eligible	0.0128%	7,814
Admixed American	0.00666%	15,008
East Asian	0.00446%	22,438
African / African-American	0.00133%	75,074
European (non-Finnish)	0.000932%	107,277

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: F2
Protein: p.Phe342=
Coding: c.1026C>T
MANE Select: NM_000506
dbSNP: rs765684282
Type: single nucleotide variant
Location: chr11:46726733 (GRCh38)
Gene constraint: LOEUF 0.552 · pLI 0.15 (gnomAD)
Structure: AlphaFold pLDDT 84.37 · 480 PDB
Residue 342: a turn

Full F2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

congenital prothrombin deficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Congenital factor II deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: All ages
Prevalence: <1 / 1 000 000 (Europe)

Similar variants

F2 p.Arg461Trp Pathogenic/Likely pathogenic ★★ same condition
F2 p.Arg500Gln Pathogenic ★★ ⚠ same condition
F2 p.Arg581Cys Pathogenic/Likely pathogenic ★★ same condition
F2 p.Arg596Gln Pathogenic ★★ ⚠ same condition
F2 p.Gln387Ter Pathogenic/Likely pathogenic ★★ same condition
F2 c.559+5G>A Uncertain significance ★★ same condition
F2 p.Ala17Ser Uncertain significance ★★ ⚠ same condition
F2 p.Arg124Gln Uncertain significance ★★ ⚠ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/f2-p-phe342 (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown