CSPP1 p.Arg877Cys
c.2629C>T · rs199521775 · VCV1023413
Uncertain significance
Multiple submitters
Classification
Uncertain significance
ClinVar
Review
Multiple submitters ★★☆☆
ClinVar · 2 submitters
gnomAD v4.1
Rare
rare (popmax 0.125%, sas)
Conditions
1
Joubert syndrome 21
Computational evidence
| Protein change | ||
| Missense predictors do not apply to this variant type; conservation carries the signal. | ||
| REVEL | 0.029 | moderately benign-leaning |
|---|---|---|
| Splicing | ||
| SpliceAI | — | not assessed · no allele here is in the release |
| Constraint at this position | ||
| Conservation | phyloP 6.1 | GERP 1.6, phastCons 1 |
| Regional constraint | o/e 0.96 | unconstrained · MANE · 121 kb · p 0.15 · regional, not allelic |
| Overall | ||
| CADD | 23.5 | PHRED · no single calibrated threshold — expert panels disagree |
Population frequency
gnomAD v4.1 · exomes + genomes
Grpmax group
0.125%
South Asian · 114/90,852 alleles
Filtering AF
0.107%
ClinGen BA1/BS1 input
FAF95, joint · FAF99 0.0997%
Overall
0.0102%
163/1,604,778 alleles · rare
| Ancestry group | Frequency | 1 in |
|---|---|---|
| South Asiangrpmax | 0.125% | 797 |
| African / African-American | 0.0334% | 2,993 |
| Middle Eastern | 0.0165% | 6,048 |
| Remaining individualsnot grpmax-eligible | 0.0129% | 7,774 |
| Admixed American | 0.00167% | 60,000 |
| Finnishnot grpmax-eligible | 0.00156% | 63,922 |
| European (non-Finnish) | 0.00111% | 90,129 |
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
- CSPP1
- Protein
- p.Arg877Cys
- Coding
- c.2629C>T
- MANE Select
- NM_001382391
- dbSNP
- rs199521775
- Type
- single nucleotide variant
- Location
- chr8:67161901 (GRCh38)
- Gene constraint
- LOEUF 0.876 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
- Structure
- AlphaFold pLDDT 57.34
Similar variants
- CSPP1 p.Arg877= Likely benign ★★ same residue
- CSPP1 p.Arg877His Benign ★★ same residue
- CSPP1 c.1022+1G>T Likely pathogenic ★★ same condition
- CSPP1 c.1187+1G>A Pathogenic/Likely pathogenic ★★ same condition
- CSPP1 c.1497-2A>C Likely pathogenic ★★ same condition
- CSPP1 c.1697+1G>T Pathogenic/Likely pathogenic ★★ same condition
- CSPP1 c.2968+1G>A Pathogenic ★★ same condition
- CSPP1 c.2968+1G>T 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/cspp1-p-arg877cys (accessed [today's date]).
Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown