Is CCNO p.Ser66Pro (c.196T>C) pathogenic?

CCNO p.Ser66Pro (c.196T>C) is classified Uncertain significance in CCNO (ClinVar, Single submitter, 1 submitter; last evaluated 2022-05-28). AlphaMissense: likely benign (0.0923); Absent from gnomAD v4.1; Associated with primary ciliary dyskinesia.

What condition is associated with CCNO p.Ser66Pro (c.196T>C)?

CCNO p.Ser66Pro (c.196T>C) is associated with primary ciliary dyskinesia (ClinVar).

How common is CCNO p.Ser66Pro (c.196T>C) in the general population?

CCNO p.Ser66Pro (c.196T>C) is absent from gnomAD v4.1 (gnomAD).

How is Primary ciliary dyskinesia inherited?

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

What do computational predictors say about CCNO p.Ser66Pro (c.196T>C)?

AlphaMissense predicts likely benign (score 0.0923) — an in-silico prediction, not a clinical call.

CCNO p.Ser66Pro

c.196T>C · rs1488154964 · VCV2000171

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0923 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

primary ciliary dyskinesia

Computational evidence

Protein change
AlphaMissense	0.0923	likely benign
REVEL	0.03	moderately benign-leaning
SaProt	LLR -6.39	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 5.2	GERP 1.7, phastCons 1
Regional constraint	o/e 1.14	unconstrained · MANE · 2,145 bp · p 0.0026 · regional, not allelic
Overall
CADD	23.3	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

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: CCNO
Protein: p.Ser66Pro
Coding: c.196T>C
MANE Select: NM_021147
dbSNP: rs1488154964
Type: single nucleotide variant
Location: chr5:55233328 (GRCh38)
Gene constraint: LOEUF 1.698 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 79.06
Residue 66: 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.Ser66= Likely benign ★ same residue
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

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-ser66pro (accessed [today's date]).

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