Is GPHN p.Pro400= (c.1200C>T) pathogenic?

GPHN p.Pro400= (c.1200C>T) is classified Likely benign in GPHN (ClinVar, Multiple submitters, 2 submitters; last evaluated 2026-02-02). Very rare (popmax 8.54e-05%, nfe); Associated with sulfite oxidase deficiency due to molybdenum cofactor deficiency type C.

What condition is associated with GPHN p.Pro400= (c.1200C>T)?

GPHN p.Pro400= (c.1200C>T) is associated with sulfite oxidase deficiency due to molybdenum cofactor deficiency type C (ClinVar).

How common is GPHN p.Pro400= (c.1200C>T) in the general population?

GPHN p.Pro400= (c.1200C>T) is very rare (popmax 8.54e-05%, nfe) (gnomAD).

GPHN p.Pro400=

c.1200C>T · rs2543059547 · VCV1955929

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 8.54e-05%, nfe)

Conditions

sulfite oxidase deficiency due to molybdenum cofactor deficiency type C

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 -2.5	GERP -2.7
Overall
CADD	4.818	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 8.54e-05% European (non-Finnish) · 1/1,170,884 alleles

Overall 6.23e-05% 1/1,604,002 alleles · very rare exomes 1/1,451,962 · genomes 0/152,040 · joint denominator

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: GPHN
Protein: p.Pro400=
Coding: c.1200C>T
MANE Select: NM_020806
dbSNP: rs2543059547
Type: single nucleotide variant
Location: chr14:67089038 (GRCh38)
Gene constraint: LOEUF 0.24 · pLI 1.00 · ClinGen HI 1/3 (gnomAD)
Structure: AlphaFold pLDDT 84.15 · 1 PDB
Residue 400: the 'mpt adenylyltransferase' region

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

Disease context

sulfite oxidase deficiency due to molybdenum cofactor deficiency type C — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

GPHN p.Pro400His Uncertain significance ★ ⚠ same residue
GPHN p.Pro400Ser Uncertain significance ★ ⚠ same residue
GPHN c.828+1G>A Likely pathogenic ★★ same condition
GPHN p.Tyr56Ter Pathogenic/Likely pathogenic ★★ same condition
GPHN c.1413+3A>G Uncertain significance ★★ same condition
GPHN p.Ala239Thr Uncertain significance ★★ ⚠ same condition
GPHN p.Ala448Ser Uncertain significance ★★ ⚠ same condition
GPHN p.Ala55Ser 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/gphn-p-pro400 (accessed [today's date]).

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