# NM_024664.4(PPCS):c.205T>C (p.Ser69Pro)

https://sugi.bio/variant/ppcs-p-ser69pro

## Summary

**PPCS p.Ser69Pro (c.205T>C)** is classified **Uncertain significance** in PPCS (ClinVar, Single submitter, 1 submitter; last evaluated 2022-02-07). AlphaMissense: likely pathogenic (0.9446); Very rare (popmax 0.00167%, amr).

**At a glance:** Uncertain significance · review: Single submitter · rsID rs1156505243 · 1 submitter · AlphaMissense likely pathogenic · very rare (popmax 0.00167%, amr)

## For patients & families {#patients}

This is a change in the PPCS gene that is currently of uncertain significance — a definitive interpretation has not yet been established, submitted by 1 submitter.

*Reference information, not medical advice, and not a prediction for any individual. A genetic counselor or clinician can interpret what it means for you and your family.*

**Support & next steps:** [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [PPCS](https://sugi.bio/atlas/gene/PPCS/) |
| Protein change (HGVS p.) | p.Ser69Pro |
| Coding change (HGVS c.) | c.205T>C |
| MANE Select transcript | [NM_024664](https://www.ncbi.nlm.nih.gov/nuccore/NM_024664) |
| dbSNP | [rs1156505243](https://www.ncbi.nlm.nih.gov/snp/rs1156505243/) |
| Variant type | single nucleotide variant |
| Location | chr1:42456770-42456770 (GRCh38) |
| ClinVar | [VCV2054986](https://www.ncbi.nlm.nih.gov/clinvar/variation/2054986/) |

**All HGVS expressions:** `NC_000001.10:g.42922441T>C`, `NC_000001.11:g.42456770T>C`, `NG_163395.1:g.257T>C`, `NG_163396.1:g.97T>C`, `NM_001077447.3:c.-12+142T>C`, `NM_001287506.1:c.-12+271T>C`, `NM_001287507.1:c.-328+271T>C`, `NM_001287508.2:c.-12+46T>C`, `NM_001287509.2:c.-12+187T>C`, `NM_001287510.2:c.-488T>C`, `NM_001287511.2:c.205T>C`, `NM_001355226.2:c.-984+271T>C`, `NM_024664.4:c.205T>C`

## Computational & population evidence {#evidence}

**Concordance:** ClinVar classifies this **uncertain**; the computational predictors unanimously lean **damaging** — a triage signal, not a reclassification.

- AlphaMissense **likely pathogenic** (0.9446)
- REVEL 0.832 (moderately pathogenic-leaning) — agrees with AlphaMissense
- SaProt LLR -16.174 (damaging) — agrees with AlphaMissense
- → **In-silico consensus:** AlphaMissense, REVEL and SaProt all call this damaging
- Conservation: phyloP 7.85, GERP 2.13, phastCons 1 — highly conserved (agrees)
- CADD: **PHRED 26.1**. No single ClinGen-calibrated threshold exists and the expert panels that use CADD disagree — GUCY2D/AIPL1 require ≥ 20.0 for an untranslated-region variant, ABCA4 ≥ 28.1 for a synonymous or indel variant, the Pulmonary Hypertension panel imports Pejaver 2022's missense-calibrated numbers, and the Antibody Deficiencies panel declines CADD entirely for PIK3CD. CADD v1.7 also incorporates Zoonomia phyloP, so it partly re-expresses the conservation above. *Descriptive; no threshold applied.*
- Regional missense constraint: **o/e 1.04** across the covering region of the MANE Select transcript (42,456,566–42,457,253), spanning 687 bp. Chi-square p 0.55. Describes the region, not this allele; gnomAD v4.1.1's own constrained determination. *Descriptive; no ACMG code applied.*
- SpliceAI: **not looked up on this page** — it was served without the gene's SpliceAI index, so no lookup was made. This is a gap in this page, not in the data, and says nothing about whether a splicing effect is predicted.
- Population frequency (gnomAD v4.1): grpmax **0.00167%** (amr) · 1/59,976 in the highest group · 1/1,612,554 alleles overall — very rare (popmax 0.00167%, amr).

*Computational predictors are not independent (ClinGen Variant Classification guidance): AlphaMissense (Cheng et al. 2023) carries the ACMG weight for missense and conservation (phyloP/GERP/phastCons) for non-missense; REVEL (Pejaver-2022 calibrated strength bands) and SaProt (Su et al. 2023, structure-aware, ClinVar-independent protein language model, raw LLR) are shown as orthogonal agreement signals, not additive. For frequency, the gnomAD v4.1 grpmax filtering allele frequency (FAF95) is ClinGen's designated BA1/BS1 input (gnomAD v4 guidance v3.0, June 2025); BA1/BS1 thresholds are disease-specific, not a blanket 5%. Predictions, not a clinical determination.*

## Clinical significance {#significance}

**Uncertain significance** — review status Single submitter *(criteria provided, single submitter)*, last evaluated 2022-02-07.

**Submitter consensus:** unanimous (1/1 Uncertain significance).

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| Labcorp Genetics (formerly Invitae), Labcorp | Uncertain significance | criteria provided, single submitter | clinical testing | 2022-02-07 |

**Reported phenotype names (ClinVar):** not provided, none provided.

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-14); gnomAD v4.1 (Broad Institute, built 2026-10-06); AlphaMissense (Cheng et al. 2023, © Google DeepMind — CC BY 4.0, built 2026-01-27); REVEL (Ioannidis et al. 2016 — ODbL, built 2026-07-13); SaProt (Su et al. 2023 — MIT, built 2026-10-14); SpliceAI (Illumina — free for non-commercial use, built 2026-10-13); CADD (Rentzsch et al. 2019, University of Washington — free for non-commercial use, built 2026-10-10); Conservation (phyloP/phastCons/GERP) (UCSC hg38 470-way mammal (Hiller Lab) + Ensembl Compara, built 2026-07-12); gnomAD Non-coding Constraint (Gnocchi) (Chen et al. 2024, Broad Institute — CC0, built 2026-10-11); gnomAD Regional Missense Constraint (Broad Institute — CC0, built 2026-10-13); Pangolin (Zeng & Li 2022 — CC BY 4.0, built 2026-10-11); Repeat regions (UCSC — RepeatMasker, TRF, segmental duplications, built 2026-10-11); ClinGen (ClinGen, built 2026-09-22); UniProt (CC BY 4.0); Reactome / GO (CC BY 4.0, built 2026-09-23); MaveDB (per-record license, built 2026-10-11); CIViC (CC0, built 2026-09-22); Orphanet (Orphanet, built 2026-06-12)

*Primary record: NCBI ClinVar (variation 2054986). Classifications reflect these databases as of the page's build date and may change. Free reference use — not medical advice; consult the primary submitters and a clinician.*