# NM_024422.6(DSC2):c.1663+1G>A

https://sugi.bio/variant/dsc2-c-1663-plus-1g-a

## Summary

**DSC2 c.1663+1G>A** is classified **Likely pathogenic** in DSC2 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-06-08). Very rare (popmax 0.00134%, afr); Associated with arrhythmogenic right ventricular dysplasia 11.

**At a glance:** Likely pathogenic · review: Single submitter · 1 submitter · 1 linked condition · very rare (popmax 0.00134%, afr)

## For patients & families {#patients}

This is a change in the DSC2 gene that is considered likely disease-causing, submitted by 1 submitter, and is linked to arrhythmogenic right ventricular dysplasia 11.

*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.*

|  |  |
| --- | --- |
| Typical inheritance (of this condition) | Autosomal dominant |
| Age of onset (of this condition) | No data available |
| Diagnostic panels | DSC2 is a diagnostic-grade gene on 8 Genomics England panels |

**Support & next steps:** [Condition overview & support (NIH GARD)](https://rarediseases.info.nih.gov/diseases/0024870/index) · [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [DSC2](https://sugi.bio/atlas/gene/DSC2/) |
| Coding change (HGVS c.) | c.1663+1G>A |
| MANE Select transcript | [NM_024422](https://www.ncbi.nlm.nih.gov/nuccore/NM_024422) |
| Variant type | single nucleotide variant |
| Location | chr18:31079846-31079846 (GRCh38) |
| ClinVar | [VCV3708157](https://www.ncbi.nlm.nih.gov/clinvar/variation/3708157/) |

**All HGVS expressions:** `LRG_400:g.27580G>A`, `NC_000018.10:g.31079846C>T`, `NC_000018.9:g.28659812C>T`, `NG_008208.2:g.27580G>A`, `NM_001406506.1:c.1234+1G>A`, `NM_001406507.1:c.1234+1G>A`, `NM_004949.5:c.1663+1G>A`, `NM_024422.6:c.1663+1G>A`

## Computational & population evidence {#evidence}

**Concordance:** 1 independent predictor **concordant** with the ClinVar classification.

- **Missense predictors (AlphaMissense/REVEL/SaProt) do not apply** to this variant type — they score amino-acid substitutions only. For non-missense variants the computational signal comes from conservation and, for splice-region changes, SpliceAI (below), not from a missing predictor score.
- SpliceAI predicts **donor loss** (Δ 0.99) — consistent with the pathogenic call
- Conservation: phyloP 7.616, GERP 2.01, phastCons 1 — highly conserved position (PP3-type support)
- Molecular consequence: **canonical splice-site (±1/±2)** — a predicted loss-of-function variant. Gene population constraint: LOEUF 0.743, pLI 7.7585e-10. *Descriptive; not an applied PVS1 code.*
- CADD: **PHRED 33.0**. 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.*
- Splice region: **canonical splice dinucleotide (donor +1)** — inside the zone ClinGen GN167 excludes from BP7, so this variant must not be called benign merely for being synonymous or intronic.
- Non-coding constraint (Gnocchi): **Z -0.90**, o/e 1.07 (1 kb window 31,079,000–31,080,000). A higher Z means the window carries less variation than expected. Describes the 1 kb window, not this allele. No ClinGen expert panel references Gnocchi and no ACMG-calibrated threshold exists for it. *Descriptive; no cut-point applied.*
- SpliceAI deltas (raw): acceptor loss **0.00**, donor loss **0.99**, acceptor gain **0.00**, donor gain **0.00**. Largest is donor loss.
- SpliceAI deltas (masked): acceptor loss **0.00**, donor loss **1.00**, acceptor gain **0.00**, donor gain **0.00**.
- Pangolin: Δ**0.86** (loss), gain 0.01 / loss 0.86. Agrees with SpliceAI. An independent predictor to SpliceAI — a different model trained on different data. *Descriptive; ClinGen's SVI calibration covers SpliceAI, not Pangolin, so no ACMG code is assigned.*
- Population frequency (gnomAD v4.1): grpmax **0.00134%** (afr) · 1/74,892 in the highest group · 2/1,613,746 alleles overall — very rare (popmax 0.00134%, afr).

| Ancestry group | Allele frequency | 1 in |
| --- | --- | --- |
| African / African-American (grpmax) | 0.00134% | 74,892 |
| South Asian | 0.0011% | 91,084 |

*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}

**DSC2** population constraint: LOEUF 0.743, pLI 7.7585e-10, missense-Z 0.84916; ClinGen dosage — haploinsufficiency 1/3, triplosensitivity 0/3. *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):

- **familial isolated arrhythmogenic right ventricular dysplasia** — Definitive (AD)

## Protein context {#protein}


AlphaFold model confidence (whole protein): pLDDT 77.26, 49% of residues very-high.

**3 experimental structure(s)** (PDB): [5ERP](https://www.rcsb.org/structure/5ERP), [5J5J](https://www.rcsb.org/structure/5J5J), [7A7D](https://www.rcsb.org/structure/7A7D).

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

*Describes the biological roles of DSC2 (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.*


### Pathways affected {#pathways}

DSC2 participates in **2 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| [Formation of the cornified envelope](https://reactome.org/content/detail/R-HSA-6809371) | curated |
| [Keratinization](https://reactome.org/content/detail/R-HSA-6805567) | curated |

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

**Biological process:** cardiac muscle cell-cardiac muscle cell adhesion, bundle of His cell-Purkinje myocyte adhesion involved in cell communication, regulation of heart rate by cardiac conduction, regulation of ventricular cardiac muscle cell action potential, positive regulation of p38MAPK cascade.

## Clinical significance {#significance}

**Likely pathogenic** — review status Single submitter *(criteria provided, single submitter)*, last evaluated 2025-06-08.

**Submitter consensus:** unanimous (1/1 Likely pathogenic).

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| Labcorp Genetics (formerly Invitae), Labcorp | Likely pathogenic | criteria provided, single submitter | clinical testing | 2025-06-08 |

## Associated conditions {#conditions}

[arrhythmogenic right ventricular dysplasia 11](https://sugi.bio/atlas/disease/arrhythmogenic-right-ventricular-dysplasia-11/).

**Reported phenotype names (ClinVar):** Arrhythmogenic right ventricular dysplasia 11, ARRHYTHMOGENIC RIGHT VENTRICULAR DYSPLASIA, FAMILIAL, 11, Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy11, Arrhythmogenic right ventricular dysplasia 11 with mild palmoplantar keratoderma and woolly hair.

## Similar variants {#similar}

Related DSC2 variant pages (same residue, condition, or type): [DSC2 c.1664-1G>A](/variant/dsc2-c-1664-minus-1g-a), [DSC2 c.354+2T>A](/variant/dsc2-c-354-plus-2t-a), [DSC2 c.355-1G>A](/variant/dsc2-c-355-minus-1g-a), [DSC2 p.Gln554Ter](/variant/dsc2-p-gln554ter), [DSC2 p.Gln620Ter](/variant/dsc2-p-gln620ter), [DSC2 p.Glu127Ter](/variant/dsc2-p-glu127ter), [DSC2 p.Glu593Ter](/variant/dsc2-p-glu593ter), [DSC2 p.Ser740Ter](/variant/dsc2-p-ser740ter).

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-14); gnomAD v4.1 (Broad Institute, built 2026-10-15); 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 3708157). 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.*