# NM_000222.3(KIT):c.839C>T (p.Ala280Val)

https://sugi.bio/variant/kit-p-ala280val

## Summary

**KIT p.Ala280Val (c.839C>T)** is classified **Conflicting classifications of pathogenicity** in KIT (ClinVar, Conflicting submitters, 4 submitters; last evaluated 2025-11-24). AlphaMissense: likely benign (0.1027); Ultra-rare (popmax 0.0111%, eas); Associated with KIT-related disorder.

**At a glance:** Conflicting classifications of pathogenicity · review: Conflicting submitters · rsID rs386833402 · 4 submitters · 3 linked conditions · AlphaMissense likely benign · ultra-rare (popmax 0.0111%, eas)

## For patients & families {#patients}

This is a change in the KIT gene that is of uncertain or conflicting significance (submitters disagree on it), submitted by 4 submitters, and is linked to KIT-related disorder.

*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 | [KIT](https://sugi.bio/atlas/gene/KIT/) |
| Protein change (HGVS p.) | p.Ala280Val |
| Coding change (HGVS c.) | c.839C>T |
| MANE Select transcript | [NM_000222](https://www.ncbi.nlm.nih.gov/nuccore/NM_000222) |
| dbSNP | [rs386833402](https://www.ncbi.nlm.nih.gov/snp/rs386833402/) |
| Variant type | single nucleotide variant |
| Location | chr4:54703806-54703806 (GRCh38) |
| ClinVar | [VCV41605](https://www.ncbi.nlm.nih.gov/clinvar/variation/41605/) |

**All HGVS expressions:** `LRG_307:g.50812C>T`, `LRG_307t1:c.839C>T`, `NC_000004.11:g.55569972C>T`, `NC_000004.12:g.54703806C>T`, `NG_007456.1:g.50812C>T`, `NM_000222.3:c.839C>T`, `NM_001093772.2:c.839C>T`, `NM_001385284.1:c.842C>T`, `NM_001385285.1:c.839C>T`, `NM_001385286.1:c.839C>T`, `NM_001385288.1:c.842C>T`, `NM_001385290.1:c.842C>T`, `NM_001385292.1:c.842C>T`

## Computational & population evidence {#evidence}

**Concordance:** Mixed / partial computational evidence (see below).

- AlphaMissense **likely benign** (0.1027)
- REVEL 0.021 (moderately benign-leaning) — agrees with AlphaMissense
- SaProt LLR -8.44 (tolerated) — agrees with AlphaMissense
- → **In-silico consensus:** AlphaMissense, REVEL and SaProt all call this tolerated
- Conservation: phyloP 0.828, GERP -0.323, phastCons 0.982 — weakly conserved position
- CADD: **PHRED 14.63**. 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 0.67** across the covering region of the MANE Select transcript (54,695,538–54,727,228), spanning 31,690 bp. Chi-square p 3.4e-16. 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 **0.0111%** (eas) · FAF95 0.00438% · FAF99 0.00309% · 5/44,868 in the highest group · 39/1,613,120 alleles overall — ultra-rare (popmax 0.0111%, eas).

| Ancestry group | Allele frequency | 1 in |
| --- | --- | --- |
| East Asian (grpmax) | 0.0111% | 8,974 |
| African / African-American | 0.00935% | 10,692 |
| Admixed American | 0.005% | 19,995 |
| Remaining individuals (not grpmax-eligible) | 0.0048% | 20,817 |
| South Asian | 0.0022% | 45,531 |
| European (non-Finnish) | 0.00161% | 62,071 |

*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}

**KIT** population constraint: LOEUF 0.24, pLI 1, missense-Z 4.1661; ClinGen dosage — haploinsufficiency 3, triplosensitivity 0 (0–3 scale). *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):

- **gastrointestinal stromal tumor** — Definitive (AD)

## Protein context {#protein}

Residue **280** lies in a disulfide bond; the ig-like c2-type 3 domain.

AlphaFold model confidence (whole protein): pLDDT 78.52, 51% of residues very-high.

**65 experimental structure(s)** (PDB): [12FJ](https://www.rcsb.org/structure/12FJ), [1PKG](https://www.rcsb.org/structure/1PKG), [1T45](https://www.rcsb.org/structure/1T45), [1T46](https://www.rcsb.org/structure/1T46), [2E9W](https://www.rcsb.org/structure/2E9W), [2EC8](https://www.rcsb.org/structure/2EC8) — incl. mutant structure 3G0F.

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

*Describes the biological roles of KIT (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:** KIT's established molecular role includes transmembrane receptor protein tyrosine kinase activity. p.Ala280Val falls in the ig-like c2-type 3 domain. In Reactome, KIT is annotated in disease pathway(s) including **Constitutive Signaling by Aberrant PI3K in Cancer**, **Dasatinib-resistant KIT mutants**.

**Disease mechanism (Reactome):** KIT loss or alteration is curated in [Constitutive Signaling by Aberrant PI3K in Cancer](https://reactome.org/content/detail/R-HSA-2219530), [Dasatinib-resistant KIT mutants](https://reactome.org/content/detail/R-HSA-9669914), [Imatinib-resistant KIT mutants](https://reactome.org/content/detail/R-HSA-9669917).

### Pathways affected {#pathways}

KIT participates in **22 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| ⚕ [Constitutive Signaling by Aberrant PI3K in Cancer](https://reactome.org/content/detail/R-HSA-2219530) | curated |
| ⚕ [Dasatinib-resistant KIT mutants](https://reactome.org/content/detail/R-HSA-9669914) | curated |
| ⚕ [Imatinib-resistant KIT mutants](https://reactome.org/content/detail/R-HSA-9669917) | curated |
| ⚕ [KIT mutants bind TKIs](https://reactome.org/content/detail/R-HSA-9669921) | curated |
| ⚕ [Masitinib-resistant KIT mutants](https://reactome.org/content/detail/R-HSA-9669924) | curated |
| ⚕ [Nilotinib-resistant KIT mutants](https://reactome.org/content/detail/R-HSA-9669926) | curated |
| ⚕ [Regorafenib-resistant KIT mutants](https://reactome.org/content/detail/R-HSA-9669929) | curated |
| ⚕ [Signaling by extracellular domain mutants of KIT](https://reactome.org/content/detail/R-HSA-9680187) | curated |
| ⚕ [Signaling by juxtamembrane domain KIT mutants](https://reactome.org/content/detail/R-HSA-9669935) | curated |
| ⚕ [Signaling by kinase domain mutants of KIT](https://reactome.org/content/detail/R-HSA-9669933) | curated |
| ⚕ [Signaling by phosphorylated juxtamembrane, extracellular and kinase domain KIT mutants](https://reactome.org/content/detail/R-HSA-9670439) | curated |
| ⚕ [Sorafenib-resistant KIT mutants](https://reactome.org/content/detail/R-HSA-9669936) | curated |
| ⚕ [Sunitinib-resistant KIT mutants](https://reactome.org/content/detail/R-HSA-9669934) | curated |
| [Developmental Lineage of Mammary Gland Alveolar Cells](https://reactome.org/content/detail/R-HSA-9927426) | curated |
| [Developmental Lineage of Mammary Gland Luminal Epithelial Cells](https://reactome.org/content/detail/R-HSA-9927418) | curated |
| [PI5P, PP2A and IER3 Regulate PI3K/AKT Signaling](https://reactome.org/content/detail/R-HSA-6811558) | curated |
| [PIP3 activates AKT signaling](https://reactome.org/content/detail/R-HSA-1257604) | curated |
| [RAF/MAP kinase cascade](https://reactome.org/content/detail/R-HSA-5673001) | curated |
| [TFAP2 (AP-2) family regulates transcription of growth factors and their receptors](https://reactome.org/content/detail/R-HSA-8866910) | curated |
| [Transcriptional and post-translational regulation of MITF-M expression and activity](https://reactome.org/content/detail/R-HSA-9856649) | curated |
| [Regulation of KIT signaling](https://reactome.org/content/detail/R-HSA-1433559) | electronic |
| [Signaling by SCF-KIT](https://reactome.org/content/detail/R-HSA-1433557) | electronic |

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

**Molecular function:** transmembrane receptor protein tyrosine kinase activity, cytokine binding, protein homodimerization activity.

**Biological process:** mast cell chemotaxis, male gonad development, cytokine-mediated signaling pathway, actin cytoskeleton organization, positive regulation of mast cell cytokine production, Fc receptor signaling pathway.

## Clinical significance {#significance}

**Conflicting classifications of pathogenicity** — review status Conflicting submitters *(criteria provided, conflicting classifications)*, last evaluated 2025-11-24.

**Submitter consensus:** conflicting (3 Uncertain significance, 1 Benign).

**Submission history:** 4 submissions (2012–2025); classifications have differed over time.

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| PreventionGenetics, part of Exact Sciences | Uncertain significance | criteria provided, single submitter | clinical testing | 2023-08-29 |
| Ambry Genetics | Benign | criteria provided, single submitter | clinical testing | 2024-07-08 |
| Labcorp Genetics (formerly Invitae), Labcorp | Uncertain significance | criteria provided, single submitter | clinical testing | 2025-11-24 |
| Biesecker Lab/Clinical Genomics Section, National Institutes of Health | Uncertain significance | no assertion criteria provided | research | 2012-07-13 |

## Associated conditions {#conditions}

[KIT-related disorder](https://sugi.bio/atlas/disease/kit-related-disorder/), [gastrointestinal stromal tumor](https://sugi.bio/atlas/disease/gastrointestinal-stromal-tumor/), [hereditary neoplastic syndrome](https://sugi.bio/atlas/disease/hereditary-neoplastic-syndrome/).

**Reported phenotype names (ClinVar):** KIT-related disorder, not provided, Gastrointestinal stromal tumor, Hereditary cancer-predisposing syndrome, KIT-related condition, Hereditary Cancer Syndrome, Tumor predisposition, Neoplastic Syndromes, Hereditary, Hereditary neoplastic syndrome, none provided.

## Similar variants {#similar}

Related KIT variant pages (same residue, condition, or type): [KIT p.Ala280=](/variant/kit-p-ala280), [KIT p.Ala280Thr](/variant/kit-p-ala280thr), [KIT p.Ala621Thr](/variant/kit-p-ala621thr), [KIT p.Asp820Tyr](/variant/kit-p-asp820tyr), [KIT p.Gln190Ter](/variant/kit-p-gln190ter), [KIT p.Leu576Pro](/variant/kit-p-leu576pro), [KIT p.Lys642Glu](/variant/kit-p-lys642glu), [KIT p.Trp557Arg](/variant/kit-p-trp557arg).

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-11); 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 2026-07-14); 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 41605). 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.*