# NM_201384.3(PLEC):c.991G>C (p.Ala331Pro)

https://sugi.bio/variant/plec-p-ala331pro

## Summary

**PLEC p.Ala331Pro (c.991G>C)** is classified **Uncertain significance** in PLEC (ClinVar, Single submitter, 1 submitter; last evaluated 2022-05-31). AlphaMissense: likely benign (0.1307); Very rare (popmax 0.00167%, amr); Associated with epidermolysis bullosa simplex with nail dystrophy.

**At a glance:** Uncertain significance · review: Single submitter · rsID rs782338088 · 1 submitter · 5 linked conditions · AlphaMissense likely benign · very rare (popmax 0.00167%, amr)

## For patients & families {#patients}

This is a change in the PLEC gene that is currently of uncertain significance — a definitive interpretation has not yet been established, submitted by 1 submitter, and is linked to epidermolysis bullosa simplex with nail dystrophy.

*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:** [Condition overview & support (NIH GARD)](https://rarediseases.info.nih.gov/diseases/0025010/index) · [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [PLEC](https://sugi.bio/atlas/gene/PLEC/) |
| Protein change (HGVS p.) | p.Ala331Pro |
| Coding change (HGVS c.) | c.991G>C |
| MANE Select transcript | [NM_201384](https://www.ncbi.nlm.nih.gov/nuccore/NM_201384) |
| dbSNP | [rs782338088](https://www.ncbi.nlm.nih.gov/snp/rs782338088/) |
| Variant type | single nucleotide variant |
| Location | chr8:143934685-143934685 (GRCh38) |
| ClinVar | [VCV1945503](https://www.ncbi.nlm.nih.gov/clinvar/variation/1945503/) |

**All HGVS expressions:** `NC_000008.10:g.145008853C>G`, `NC_000008.11:g.143934685C>G`, `NG_012492.1:g.47061G>C`, `NM_000445.5:c.1072G>C`, `NM_001410941.1:c.1072G>C`, `NM_201378.4:c.949G>C`, `NM_201379.3:c.925G>C`, `NM_201380.4:c.1402G>C`, `NM_201381.3:c.895G>C`, `NM_201382.4:c.991G>C`, `NM_201383.3:c.1003G>C`, `NM_201384.3:c.991G>C`

## Computational & population evidence {#evidence}

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

- AlphaMissense **likely benign** (0.1307)
- REVEL 0.245 (benign-leaning) — agrees with AlphaMissense
- → **In-silico consensus:** AlphaMissense and REVEL both call this tolerated; SaProt makes no call
- Conservation: phyloP 5.783, phastCons 1 — highly conserved (differs from AlphaMissense)
- **SaProt:** not scored — SaProt is structure-aware and AlphaFold DB has no model for this protein. That is a property of the dataset, not of the variant, and is not evidence either way.
- ⚠ **Isoform check:** AlphaMissense is numbered on a different transcript (AM **A468P** vs ClinVar **A331P**) — the AlphaMissense read here may be for a different residue; verify against the ClinVar transcript.
- CADD: **PHRED 22.7**. 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 1.08** across the covering region of the MANE Select transcript (143,918,174–143,935,987), spanning 17,813 bp. Chi-square p 4.9e-10. Describes the region, not this allele; gnomAD v4.1.1's own constrained determination. *Descriptive; no ACMG code applied.*
- SpliceAI: **not assessed** — no allele at this position is in our SpliceAI release, either because it lies outside the scored MANE transcript scope or because every allele is below Δ0.2. We cannot tell which, so this claims neither; absence is not evidence against a splicing effect.
- Population frequency (gnomAD v4.1): grpmax **0.00167%** (amr) · 1/60,032 in the highest group · 2/1,613,018 alleles overall — very rare (popmax 0.00167%, amr).

| Ancestry group | Allele frequency | 1 in |
| --- | --- | --- |
| Admixed American (grpmax) | 0.00167% | 60,032 |
| European (non-Finnish) | 8.47e-05% | 1,179,962 |

*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.*

## Gene constraint & dosage {#gene-context}

**PLEC** population constraint: LOEUF 0.726, pLI 5.951e-44, missense-Z -2.7548. *Lower LOEUF and higher pLI indicate a gene that tolerates loss-of-function poorly; ClinGen dosage is the curated haploinsufficiency call.*

Curated gene–disease validity (ClinGen):

- **PLEC-related muscular dystrophy-epidermolysis bullosa simplex spectrum disorder** — Definitive (AR)

## Protein context {#protein}


**14 experimental structure(s)** (PDB): [1MB8](https://www.rcsb.org/structure/1MB8), [2N03](https://www.rcsb.org/structure/2N03), [2ODU](https://www.rcsb.org/structure/2ODU), [2ODV](https://www.rcsb.org/structure/2ODV), [3F7P](https://www.rcsb.org/structure/3F7P), [3PDY](https://www.rcsb.org/structure/3PDY) — incl. mutant structure 2ODV.

## What this gene does {#gene-function}

*Describes the biological roles of PLEC (the gene this variant disrupts) — not effects measured for this specific variant. A damaging variant is expected to affect these functions and pathways; the degree depends on the variant.*

**How this variant is thought to act:** PLEC's established molecular role includes RNA binding. p.Ala331Pro falls in the calponin-homology (ch) 2 domain.


### Pathways affected {#pathways}

PLEC participates in **3 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| [Assembly of collagen fibrils and other multimeric structures](https://reactome.org/content/detail/R-HSA-2022090) | curated |
| [Caspase-mediated cleavage of cytoskeletal proteins](https://reactome.org/content/detail/R-HSA-264870) | curated |
| [Type I hemidesmosome assembly](https://reactome.org/content/detail/R-HSA-446107) | curated |

### Molecular function & processes (GO — experimentally supported) {#go}

**Molecular function:** RNA binding, structural constituent of muscle, ankyrin binding, cadherin binding.

**Biological process:** hemidesmosome assembly.

## Clinical significance {#significance}

**Uncertain significance** — review status Single submitter *(criteria provided, single submitter)*, last evaluated 2022-05-31.

**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 | 2022-05-31 |

## Associated conditions {#conditions}

[epidermolysis bullosa simplex with nail dystrophy](https://sugi.bio/atlas/disease/epidermolysis-bullosa-simplex-with-nail-dystrophy/), [epidermolysis bullosa simplex 5A, Ogna type](https://sugi.bio/atlas/disease/epidermolysis-bullosa-simplex-5a-ogna-type/), [epidermolysis bullosa simplex 5B, with muscular dystrophy](https://sugi.bio/atlas/disease/epidermolysis-bullosa-simplex-5b-with-muscular-dystrophy/), [epidermolysis bullosa simplex 5C, with pyloric atresia](https://sugi.bio/atlas/disease/epidermolysis-bullosa-simplex-5c-with-pyloric-atresia/), [autosomal recessive limb-girdle muscular dystrophy type 2Q](https://sugi.bio/atlas/disease/autosomal-recessive-limb-girdle-muscular-dystrophy-type-2q/).

**Reported phenotype names (ClinVar):** Epidermolysis bullosa simplex with nail dystrophy, Autosomal recessive limb-girdle muscular dystrophy type 2Q, Epidermolysis bullosa simplex 5B, with muscular dystrophy, Epidermolysis bullosa simplex 5C, with pyloric atresia, Epidermolysis bullosa simplex, Ogna type, Epidermolysis bullosa simplex with muscular dystrophy, EPIDERMOLYSIS BULLOSA SIMPLEX AND LIMB-GIRDLE MUSCULAR DYSTROPHY, EPIDERMOLYSIS BULLOSA SIMPLEX 5A, OGNA TYPE, Pidermolysis bullosa simplex 5A, Ogna type, PLEC-Related Epidermolysis Bullosa with Pyloric Atresia.

## Similar variants {#similar}

Related PLEC variant pages (same residue, condition, or type): [PLEC p.Ala331Ser](/variant/plec-p-ala331ser), [PLEC p.Ala331Thr](/variant/plec-p-ala331thr), [PLEC p.Ala331=](/variant/plec-p-ala331), [PLEC p.Arg1490Ter](/variant/plec-p-arg1490ter), [PLEC p.Arg1973Trp](/variant/plec-p-arg1973trp), [PLEC p.Arg2027Ter](/variant/plec-p-arg2027ter), [PLEC p.Arg2292Ter](/variant/plec-p-arg2292ter), [PLEC p.Arg2324Ter](/variant/plec-p-arg2324ter).

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-14); gnomAD v4.1 (Broad Institute, built 2026-10-14); 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 1945503). 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.*