Is FGFR1 p.Pro25= (c.75G>C) pathogenic?

FGFR1 p.Pro25= (c.75G>C) is classified Likely benign in FGFR1 (ClinVar, Multiple submitters, 2 submitters; last evaluated 2024-01-01). Very rare (popmax 0.01%, amr); Associated with hypogonadotropic hypogonadism 2 with or without anosmia.

How common is FGFR1 p.Pro25= (c.75G>C) in the general population?

FGFR1 p.Pro25= (c.75G>C) is very rare (popmax 0.01%, amr) (gnomAD).

FGFR1 p.Pro25=

Q: What condition is associated with FGFR1 p.Pro25= (c.75G>C)?

FGFR1 p.Pro25= (c.75G>C) is associated with hypogonadotropic hypogonadism 2 with or without anosmia, Pfeiffer syndrome (ClinVar).

c.75G>C · rs17175757 · VCV1550374

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 0.01%, amr)

Conditions

hypogonadotropic hypogonadism 2 with or without anosmia

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 -8	GERP -4.6
Overall
CADD	0.392	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.01% Admixed American · 6/60,006 alleles

Filtering AF 0.00428% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00295%

Overall 0.000434% 7/1,613,296 alleles · very rare exomes 3/1,461,130 · genomes 4/152,166 · joint denominator

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.01%	10,001
African / African-American	0.00133%	74,918

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: FGFR1
Protein: p.Pro25=
Coding: c.75G>C
MANE Select: NM_023110
dbSNP: rs17175757
Type: single nucleotide variant
Location: chr8:38457372 (GRCh38)
Gene constraint: LOEUF 0.274 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 74.30 · 86 PDB
Residue 25: the ig-like c2-type 1 domain

Full FGFR1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

hypogonadotropic hypogonadism 2 with or without anosmia — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: Pfeiffer syndrome

Similar variants

FGFR1 p.Pro25fs Pathogenic ★ same residue
FGFR1 p.Pro25Leu Uncertain significance ★★ ⚠ same residue
FGFR1 c.1977+1G>A Pathogenic/Likely pathogenic ★★ same condition
FGFR1 c.1977+1G>T Pathogenic/Likely pathogenic ★★ same condition
FGFR1 c.448+1G>A Likely pathogenic ★★ same condition
FGFR1 c.449-6G>A Likely pathogenic ★★ same condition
FGFR1 c.91+1G>A Pathogenic/Likely pathogenic ★★ same condition
FGFR1 p.Arg209Cys Likely pathogenic ★★ 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/fgfr1-p-pro25 (accessed [today's date]).

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