Is ADAR p.Ser257= (c.771C>T) pathogenic?

ADAR p.Ser257= (c.771C>T) is classified Likely benign in ADAR (ClinVar, Multiple submitters, 3 submitters; last evaluated 2026-02-01). Very rare (popmax 0.00288%, nfe); Associated with dyschromatosis symmetrica hereditaria.

What condition is associated with ADAR p.Ser257= (c.771C>T)?

ADAR p.Ser257= (c.771C>T) is associated with dyschromatosis symmetrica hereditaria, Aicardi-Goutieres syndrome 6 (ClinVar).

How common is ADAR p.Ser257= (c.771C>T) in the general population?

ADAR p.Ser257= (c.771C>T) is very rare (popmax 0.00288%, nfe) (gnomAD).

How is Dyschromatosis symmetrica hereditaria inherited?

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

ADAR p.Ser257=

c.771C>T · rs368596210 · VCV1621462

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

gnomAD v4.1

Rare

very rare (popmax 0.00288%, nfe)

Conditions

dyschromatosis symmetrica hereditaria

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 0.019	GERP -2.6
Overall
CADD	3.737	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00288% European (non-Finnish) · 34/1,180,034 alleles

Filtering AF 0.00207% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00183%

Overall 0.00223% 36/1,614,020 alleles · very rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.00288%	34,707
Remaining individualsnot grpmax-eligible	0.0016%	62,486
South Asian	0.0011%	91,088

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: ADAR
Protein: p.Ser257=
Coding: c.771C>T
MANE Select: NM_001111
dbSNP: rs368596210
Type: single nucleotide variant
Location: chr1:154601871 (GRCh38)
Gene constraint: LOEUF 0.449 · pLI 1.00 (gnomAD)
Structure: AlphaFold pLDDT 68.86 · 24 PDB

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

Disease context

dyschromatosis symmetrica hereditaria — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: Aicardi-Goutieres syndrome 6

For Dyschromatosis symmetrica hereditaria (Orphanet):

Inheritance: Autosomal dominant
Onset: Childhood

Similar variants

ADAR p.Ser257Arg Uncertain significance ★ ⚠ same residue
ADAR c.2885+1G>A Likely pathogenic ★★ same condition
ADAR p.Arg1078Cys Pathogenic ★★ same condition
ADAR p.Arg1096Ter Pathogenic/Likely pathogenic ★★ same condition
ADAR p.Arg328Ter Pathogenic ★★ same condition
ADAR p.Arg360Ter Pathogenic/Likely pathogenic ★★ same condition
ADAR p.Arg474Ter Pathogenic ★★ same condition
ADAR p.Gln559Ter 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/adar-p-ser257 (accessed [today's date]).

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