Is QDPR p.Ser99= (c.297T>C) pathogenic?

QDPR p.Ser99= (c.297T>C) is classified Conflicting classifications of pathogenicity in QDPR (ClinVar, Conflicting submitters, 2 submitters; last evaluated 2025-11-10). Very rare (popmax 6.2e-05%); Associated with dihydropteridine reductase deficiency.

What condition is associated with QDPR p.Ser99= (c.297T>C)?

QDPR p.Ser99= (c.297T>C) is associated with dihydropteridine reductase deficiency (ClinVar).

How common is QDPR p.Ser99= (c.297T>C) in the general population?

QDPR p.Ser99= (c.297T>C) is very rare (popmax 6.2e-05%) (gnomAD).

QDPR p.Ser99=

Q: How is Hyperphenylalaninemia due to tetrahydrobiopterin deficiency inherited?

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

c.297T>C · rs1309099253 · VCV900896

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 6.2e-05%)

Conditions

dihydropteridine reductase deficiency

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
REVEL	0.013	strongly benign-leaning
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 1.1	GERP -5, phastCons 1
Overall
CADD	11.29	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 6.2e-05%

Overall 6.2e-05% 1/1,614,042 alleles · very rare exomes 1/1,461,840 · genomes 0/152,202 · 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: QDPR
Protein: p.Ser99=
Coding: c.297T>C
MANE Select: NM_000320
dbSNP: rs1309099253
Type: single nucleotide variant
Location: chr4:17501858 (GRCh38)
Gene constraint: LOEUF 0.984 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 96.43 · 2 PDB

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

Disease context

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

For Hyperphenylalaninemia due to tetrahydrobiopterin deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy, Neonatal
Prevalence: 1-9 / 1 000 000 (Japan)

Similar variants

QDPR p.Ser99Phe Uncertain significance ★ ⚠ same residue
QDPR c.436+2552A>G Pathogenic ★★ same condition
QDPR c.545+1G>A Pathogenic ★★ same condition
QDPR c.546-1G>A Likely pathogenic ★★ same condition
QDPR p.Arg221Ter Pathogenic ★★ same condition
QDPR p.His158Tyr Pathogenic/Likely pathogenic ★★ same condition
QDPR p.Phe212Ser Likely pathogenic ★★ same condition
QDPR p.Ser115Leu Pathogenic/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/qdpr-p-ser99 (accessed [today's date]).

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