Is CCNO p.Pro28= (c.84G>A) pathogenic?

CCNO p.Pro28= (c.84G>A) is classified Likely benign in CCNO (ClinVar, Single submitter, 1 submitter; last evaluated 2024-02-09). Ultra-rare (popmax 0.0287%, amr); Associated with primary ciliary dyskinesia.

What condition is associated with CCNO p.Pro28= (c.84G>A)?

CCNO p.Pro28= (c.84G>A) is associated with primary ciliary dyskinesia (ClinVar).

How common is CCNO p.Pro28= (c.84G>A) in the general population?

CCNO p.Pro28= (c.84G>A) is ultra-rare (popmax 0.0287%, amr) (gnomAD).

How is Primary ciliary dyskinesia inherited?

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

CCNO p.Pro28=

c.84G>A · rs755568469 · VCV2185291

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0287%, amr)

Conditions

primary ciliary dyskinesia

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 -7.9	GERP -2.2
Overall
CADD	8.785	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0287% Admixed American · 17/59,156 alleles

Filtering AF 0.0182% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0149%

Overall 0.00112% 18/1,605,028 alleles · ultra-rare

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.0287%	3,480
South Asian	0.00111%	89,776

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: CCNO
Protein: p.Pro28=
Coding: c.84G>A
MANE Select: NM_021147
dbSNP: rs755568469
Type: single nucleotide variant
Location: chr5:55233440 (GRCh38)
Gene constraint: LOEUF 1.698 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 79.06
Residue 28: the 'disordered' region

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

Disease context

primary ciliary dyskinesia — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Primary ciliary dyskinesia (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive, X-linked recessive
Onset: Neonatal
Prevalence: 1-5 / 10 000 (Pakistan)

Similar variants

CCNO p.Gln103Ter Pathogenic ★★ same condition
CCNO p.Ala14Ser Uncertain significance ★★ ⚠ same condition
CCNO p.Ala202Val Uncertain significance ★★ ⚠ same condition
CCNO p.Ala230Thr Uncertain significance ★★ ⚠ same condition
CCNO p.Ala258Gly Uncertain significance ★★ ⚠ same condition
CCNO p.Arg124Leu Uncertain significance ★★ ⚠ same condition
CCNO p.Arg124Trp Uncertain significance ★★ ⚠ same condition
CCNO p.Arg133Leu 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/ccno-p-pro28 (accessed [today's date]).

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