Is UNG p.Ser63= (c.189C>G) pathogenic?

UNG p.Ser63= (c.189C>G) is classified Likely benign in UNG (ClinVar, Single submitter, 1 submitter; last evaluated 2023-04-21). Absent from gnomAD v4.1; Associated with hyper-IgM syndrome type 5.

What condition is associated with UNG p.Ser63= (c.189C>G)?

UNG p.Ser63= (c.189C>G) is associated with hyper-IgM syndrome type 5 (ClinVar).

How common is UNG p.Ser63= (c.189C>G) in the general population?

UNG p.Ser63= (c.189C>G) is absent from gnomAD v4.1 (gnomAD).

UNG p.Ser63=

c.189C>G · rs2499977818 · VCV2999597

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

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 -0.78	GERP -1.8
Overall
CADD	6.019	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: UNG
Protein: p.Ser63=
Coding: c.189C>G
MANE Select: NM_080911
dbSNP: rs2499977818
Type: single nucleotide variant
Location: chr12:109098488 (GRCh38)
Gene constraint: LOEUF 1.22 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 86.52 · 24 PDB
Residue 63: the 'disordered' region

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.Ser63Phe 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-ser63 (accessed [today's date]).

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