Is UNG p.Ser225= (c.675T>G) pathogenic?

UNG p.Ser225= (c.675T>G) is classified Likely benign in UNG (ClinVar, Single submitter, 1 submitter; last evaluated 2025-11-10). Ultra-rare (popmax 0.0223%, eas); Associated with hyper-IgM syndrome type 5.

What condition is associated with UNG p.Ser225= (c.675T>G)?

UNG p.Ser225= (c.675T>G) is associated with hyper-IgM syndrome type 5 (ClinVar).

How common is UNG p.Ser225= (c.675T>G) in the general population?

UNG p.Ser225= (c.675T>G) is ultra-rare (popmax 0.0223%, eas) (gnomAD).

UNG p.Ser225=

c.675T>G · VCV4708154

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0223%, eas)

Conditions

hyper-IgM syndrome type 5

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 -1.1	GERP -0.4, phastCons 0.002
Overall
CADD	6.721	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0223% East Asian · 10/44,882 alleles

Filtering AF 0.012% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00916%

Overall 0.000684% 10/1,461,882 alleles · ultra-rare

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: UNG
Protein: p.Ser225=
Coding: c.675T>G
MANE Select: NM_080911
Type: single nucleotide variant
Location: chr12:109103485 (GRCh38)
Gene constraint: LOEUF 1.22 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 86.52 · 24 PDB
Residue 225: a turn

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

Disease context

hyper-IgM syndrome type 5 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

UNG p.Ser225Phe Uncertain significance ★ ⚠ same residue
UNG c.623-9T>A Uncertain significance ★★ same condition
UNG c.801+5G>A Uncertain significance ★★ same condition
UNG p.Ala21Thr Uncertain significance ★★ ⚠ same condition
UNG p.Ala87Val Uncertain significance ★★ ⚠ same condition
UNG p.Arg122Ser Uncertain significance ★★ ⚠ same condition
UNG p.Arg269Trp Uncertain significance ★★ ⚠ same condition
UNG p.Asn77Lys 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/ung-p-ser225 (accessed [today's date]).

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