Is CPLANE1 p.Val221Ala (c.662T>C) pathogenic?

CPLANE1 p.Val221Ala (c.662T>C) is classified Benign/Likely benign in CPLANE1 (ClinVar, Multiple submitters, 10 submitters; last evaluated 2026-01-20). AlphaMissense: likely benign (0.0944); Rare (popmax 0.495%, sas); Associated with Joubert syndrome 17.

What condition is associated with CPLANE1 p.Val221Ala (c.662T>C)?

CPLANE1 p.Val221Ala (c.662T>C) is associated with Joubert syndrome 17 (ClinVar).

How common is CPLANE1 p.Val221Ala (c.662T>C) in the general population?

CPLANE1 p.Val221Ala (c.662T>C) is rare (popmax 0.495%, sas) (gnomAD).

What do computational predictors say about CPLANE1 p.Val221Ala (c.662T>C)?

AlphaMissense predicts likely benign (score 0.0944) — an in-silico prediction, not a clinical call.

CPLANE1 p.Val221Ala

c.662T>C · rs370118778 · VCV353466

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 10 submitters

AlphaMissense

likely benign

0.0944 · ACMG-weighted

gnomAD v4.1

Rare

rare (popmax 0.495%, sas)

Missense predictors

0/2 damaging

AlphaMissense, REVEL

Conditions

Joubert syndrome 17

Computational evidence

Protein change
AlphaMissense	0.0944	likely benign
REVEL	0.017	moderately benign-leaning
⇒ AlphaMissense and REVEL both call this tolerated.
Splicing
SpliceAI	Δ0.24	donor gain · deltas
Constraint at this position
Conservation	phyloP 1.7	GERP -3.5, phastCons 0.012
Regional constraint	o/e 0.92	unconstrained · MANE · 139 kb · p 2.3e-06 · regional, not allelic
Overall
CADD	13.2	PHRED · no single calibrated threshold — expert panels disagree

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

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.495% South Asian · 409/82,552 alleles

Filtering AF 0.456% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.44%

Overall 0.0318% 490/1,541,016 alleles · rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.495%	202
Middle Eastern	0.167%	598
Remaining individualsnot grpmax-eligible	0.0385%	2,596
European (non-Finnish)	0.00403%	24,822
Admixed American	0.00206%	48,652
African / African-American	0.00138%	72,472

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: CPLANE1
Protein: p.Val221Ala
Coding: c.662T>C
MANE Select: NM_001384732
dbSNP: rs370118778
Type: single nucleotide variant
Location: chr5:37243028 (GRCh38)
Gene constraint: LOEUF 0.728 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)

Full CPLANE1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Joubert syndrome 17 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

CPLANE1 p.Val221= Likely benign ★ same residue
CPLANE1 c.1372-2A>G Pathogenic/Likely pathogenic ★★ same condition
CPLANE1 c.2291+1G>A Likely pathogenic ★★ same condition
CPLANE1 c.2291+2T>C Pathogenic/Likely pathogenic ★★ same condition
CPLANE1 c.2292-1G>A Likely pathogenic ★★ same condition
CPLANE1 c.2500+1G>A Likely pathogenic ★★ same condition
CPLANE1 c.3290-2A>G Pathogenic/Likely pathogenic ★★ same condition
CPLANE1 c.3673-1G>C Pathogenic/Likely 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/cplane1-p-val221ala (accessed [today's date]).

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