Is CD40 c.256+20A>G pathogenic?

CD40 c.256+20A>G is classified Likely benign in CD40 (ClinVar, Single submitter, 1 submitter; last evaluated 2024-04-24). Very rare (popmax 0.000763%, nfe).

How common is CD40 c.256+20A>G in the general population?

CD40 c.256+20A>G is very rare (popmax 0.000763%, nfe) (gnomAD).

CD40 c.256+20A>G

rs923172384 · VCV3010299

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.000763%, nfe)

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
Splice region	donor +20	near-intronic (+20 nt from the splice site)
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -1.4	GERP -3
Non-coding constraint	Z 4.96	1 kb window · o/e 0.67 · regional · uncalibrated
Overall
CADD	4.945	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000763% European (non-Finnish) · 9/1,180,032 alleles

Filtering AF 0.000359% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00026%

Overall 0.000616% 9/1,461,788 alleles · very 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: CD40
Coding: c.256+20A>G
MANE Select: NM_001250
dbSNP: rs923172384
Type: single nucleotide variant
Location: chr20:46122378 (GRCh38)
Gene constraint: LOEUF 0.677 · pLI 0.03 (gnomAD)
Structure: AlphaFold pLDDT 81.10 · 14 PDB

Full CD40 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

CD40 c.256+5G>A Uncertain significance ★★ same type
CD40 c.*178G>A Uncertain significance ★★ same type
CD40 c.*547A>T Uncertain significance ★★ same type
CD40 p.Ala25Ser Uncertain significance ★★ ⚠ same type
CD40 p.Arg123His Uncertain significance ★★ ⚠ same type
CD40 p.Asn180Lys Uncertain significance ★★ ⚠ same type
CD40 p.Glu159Lys Uncertain significance ★★ ⚠ same type
CD40 p.Ile204Val Uncertain significance ★★ ⚠ same type

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/cd40-c-256-plus-20a-g (accessed [today's date]).

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