# NM_000546.6(TP53):c.414C>T (p.Ala138=)

https://sugi.bio/variant/tp53-p-ala138

## Summary

**TP53 p.Ala138= (c.414C>T)** is classified **Likely benign** in TP53 (ClinVar, Expert panel, 4 submitters; last evaluated 2025-06-05). Very rare (popmax 8.47e-05%, nfe); Associated with Li-Fraumeni syndrome.

**At a glance:** Likely benign · review: Expert panel · rsID rs1555526254 · 4 submitters · 2 linked conditions · very rare (popmax 8.47e-05%, nfe)

## For patients & families {#patients}

This is a change in the TP53 gene that is classified as likely benign — not considered disease-causing, submitted by 4 submitters, and is linked to Li-Fraumeni syndrome.

*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) | All ages |
| Prevalence | 1-9 / 100 000 (United Kingdom) |
| Clinical trials | 21 registered for this condition — see ClinicalTrials.gov |
| Diagnostic panels | TP53 is a diagnostic-grade gene on 19 Genomics England panels |

**Commonly reported features of Li-Fraumeni syndrome** (across patients with this condition; presentation varies — frequencies from Orphanet):

- Neoplasm — Very frequent (99-80%)
- Breast carcinoma — Frequent (79-30%)
- Leukemia — Occasional (29-5%)
- Lymphoma — Occasional (29-5%)
- Osteosarcoma — Occasional (29-5%)
- Rhabdomyosarcoma — Occasional (29-5%)
- Ependymoma — Occasional (29-5%)
- Adrenocortical carcinoma — Occasional (29-5%)

**Support & next steps:** [Condition overview & support (NIH GARD)](https://rarediseases.info.nih.gov/diseases/0006902/index) · [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [TP53](https://sugi.bio/atlas/gene/TP53/) |
| Protein change (HGVS p.) | p.Ala138= |
| Coding change (HGVS c.) | c.414C>T |
| MANE Select transcript | [NM_000546](https://www.ncbi.nlm.nih.gov/nuccore/NM_000546) |
| dbSNP | [rs1555526254](https://www.ncbi.nlm.nih.gov/snp/rs1555526254/) |
| Variant type | single nucleotide variant |
| Location | chr17:7675198-7675198 (GRCh38) |
| ClinVar | [VCV482234](https://www.ncbi.nlm.nih.gov/clinvar/variation/482234/) |

**All HGVS expressions:** `LRG_321:g.17353C>T`, `NC_000017.10:g.7578516G>A`, `NC_000017.11:g.7675198G>A`, `NG_017013.2:g.17353C>T`, `NM_000546.6:c.414C>T`, `NM_001126112.3:c.414C>T`, `NM_001126113.3:c.414C>T`, `NM_001126114.3:c.414C>T`, `NM_001126115.2:c.18C>T`, `NM_001126116.2:c.18C>T`, `NM_001126117.2:c.18C>T`, `NM_001126118.2:c.297C>T`, `NM_001276695.3:c.297C>T`, `NM_001276696.3:c.297C>T`, `NM_001276697.3:c.-64C>T`, `NM_001276698.3:c.-64C>T`, `NM_001276699.3:c.-64C>T`, `NM_001276760.3:c.297C>T`, `NM_001276761.3:c.297C>T`

## Computational & population evidence {#evidence}

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

- **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 (below), not from a missing predictor score.
- Conservation: phyloP -1.582, GERP -4.63 — not a conserved position (phyloP < 0.1, ACGS BP7 cut)
- CADD: **PHRED 3.553**. 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.*
- 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 **8.47e-05%** (nfe) · 1/1,180,016 in the highest group · 1/1,614,158 alleles overall — very rare (popmax 8.47e-05%, nfe).

*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}

**TP53** population constraint: LOEUF 0.449, pLI 0.99798, missense-Z 1.1539; ClinGen dosage — haploinsufficiency 3/3, 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):

- **Li-Fraumeni syndrome** — Definitive (AD)

## Protein context {#protein}

Residue **138** lies in a DNA-binding region; the 'interaction with axin1' region; the 'interaction with ccar2' region; a UniProt-annotated variant site (in sporadic cancers; somatic mutation); a UniProt-annotated variant site (in lfs; germline mutation and in sporadic cancers; somatic mutation); a UniProt-annotated variant site (in lfs; germline mutation); the 'interaction with hipk1' region; the 'required for interaction with znf385a' region; the 'required for interaction with fbxo42' region.

AlphaFold model confidence (whole protein): pLDDT 75.83, 54% of residues very-high.

**321 experimental structure(s)** (PDB): [1A1U](https://www.rcsb.org/structure/1A1U), [1AIE](https://www.rcsb.org/structure/1AIE), [1C26](https://www.rcsb.org/structure/1C26), [1DT7](https://www.rcsb.org/structure/1DT7), [1GZH](https://www.rcsb.org/structure/1GZH), [1H26](https://www.rcsb.org/structure/1H26) — incl. mutant structure 1A1U.

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

*Describes the biological roles of TP53 (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:** TP53's established molecular role includes transcription cis-regulatory region binding. p.Ala138= falls in a DNA-binding region. In Reactome, TP53 is annotated in disease pathway(s) including **Loss of function of TP53 in cancer due to loss of tetramerization ability**, **Signaling by ALK fusions and activated point mutants**.

**Disease mechanism (Reactome):** TP53 loss or alteration is curated in [Loss of function of TP53 in cancer due to loss of tetramerization ability](https://reactome.org/content/detail/R-HSA-9723905), [Signaling by ALK fusions and activated point mutants](https://reactome.org/content/detail/R-HSA-9725370).

### Pathways affected {#pathways}

TP53 participates in **47 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| ⚕ [Loss of function of TP53 in cancer due to loss of tetramerization ability](https://reactome.org/content/detail/R-HSA-9723905) | curated |
| ⚕ [Signaling by ALK fusions and activated point mutants](https://reactome.org/content/detail/R-HSA-9725370) | curated |
| [Activation of NOXA and translocation to mitochondria](https://reactome.org/content/detail/R-HSA-111448) | curated |
| [Activation of PUMA and translocation to mitochondria](https://reactome.org/content/detail/R-HSA-139915) | curated |
| [Autodegradation of the E3 ubiquitin ligase COP1](https://reactome.org/content/detail/R-HSA-349425) | curated |
| [DNA Damage/Telomere Stress Induced Senescence](https://reactome.org/content/detail/R-HSA-2559586) | curated |
| [Formation of Senescence-Associated Heterochromatin Foci (SAHF)](https://reactome.org/content/detail/R-HSA-2559584) | curated |
| [G2/M Checkpoints](https://reactome.org/content/detail/R-HSA-69481) | curated |
| [G2/M DNA damage checkpoint](https://reactome.org/content/detail/R-HSA-69473) | curated |
| [Interleukin-4 and Interleukin-13 signaling](https://reactome.org/content/detail/R-HSA-6785807) | curated |
| [Negative transcriptional regulation of urea cycle enzymes](https://reactome.org/content/detail/R-HSA-9988426) | curated |
| [Oncogene Induced Senescence](https://reactome.org/content/detail/R-HSA-2559585) | curated |
| [Ovarian tumor domain proteases](https://reactome.org/content/detail/R-HSA-5689896) | curated |
| [Oxidative Stress Induced Senescence](https://reactome.org/content/detail/R-HSA-2559580) | curated |
| [PI5P Regulates TP53 Acetylation](https://reactome.org/content/detail/R-HSA-6811555) | curated |
| [PKR-mediated signaling](https://reactome.org/content/detail/R-HSA-9833482) | curated |
| [Pre-NOTCH Transcription and Translation](https://reactome.org/content/detail/R-HSA-1912408) | curated |
| [Pyroptosis](https://reactome.org/content/detail/R-HSA-5620971) | curated |
| [RUNX3 regulates CDKN1A transcription](https://reactome.org/content/detail/R-HSA-8941855) | curated |
| [Recruitment and ATM-mediated phosphorylation of repair and signaling proteins at DNA double strand breaks](https://reactome.org/content/detail/R-HSA-5693565) | curated |
| [Regulation of NF-kappa B signaling](https://reactome.org/content/detail/R-HSA-9758274) | curated |
| [Regulation of TP53 Activity through Acetylation](https://reactome.org/content/detail/R-HSA-6804758) | curated |
| [Regulation of TP53 Activity through Association with Co-factors](https://reactome.org/content/detail/R-HSA-6804759) | curated |
| [Regulation of TP53 Activity through Methylation](https://reactome.org/content/detail/R-HSA-6804760) | curated |
| [Regulation of TP53 Activity through Phosphorylation](https://reactome.org/content/detail/R-HSA-6804756) | curated |
| [Regulation of TP53 Degradation](https://reactome.org/content/detail/R-HSA-6804757) | curated |
| [Regulation of TP53 Expression](https://reactome.org/content/detail/R-HSA-6804754) | curated |
| [SUMOylation of transcription factors](https://reactome.org/content/detail/R-HSA-3232118) | curated |
| [Stabilization of p53](https://reactome.org/content/detail/R-HSA-69541) | curated |
| [TP53 Regulates Metabolic Genes](https://reactome.org/content/detail/R-HSA-5628897) | curated |
| [TP53 Regulates Transcription of Caspase Activators and Caspases](https://reactome.org/content/detail/R-HSA-6803207) | curated |
| [TP53 Regulates Transcription of DNA Repair Genes](https://reactome.org/content/detail/R-HSA-6796648) | curated |
| [TP53 Regulates Transcription of Death Receptors and Ligands](https://reactome.org/content/detail/R-HSA-6803211) | curated |
| [TP53 Regulates Transcription of Genes Involved in Cytochrome C Release](https://reactome.org/content/detail/R-HSA-6803204) | curated |
| [TP53 Regulates Transcription of Genes Involved in G1 Cell Cycle Arrest](https://reactome.org/content/detail/R-HSA-6804116) | curated |
| [TP53 Regulates Transcription of Genes Involved in G2 Cell Cycle Arrest](https://reactome.org/content/detail/R-HSA-6804114) | curated |
| [TP53 regulates transcription of additional cell cycle genes whose exact role in the p53 pathway remain uncertain](https://reactome.org/content/detail/R-HSA-6804115) | curated |
| [TP53 regulates transcription of several additional cell death genes whose specific roles in p53-dependent apoptosis remain uncertain](https://reactome.org/content/detail/R-HSA-6803205) | curated |
| [The role of GTSE1 in G2/M progression after G2 checkpoint](https://reactome.org/content/detail/R-HSA-8852276) | curated |
| [Transcriptional  activation of  cell cycle inhibitor p21 ](https://reactome.org/content/detail/R-HSA-69895) | curated |
| [Transcriptional Regulation by VENTX](https://reactome.org/content/detail/R-HSA-8853884) | curated |
| [Ub-specific processing proteases](https://reactome.org/content/detail/R-HSA-5689880) | curated |
| [Association of TriC/CCT with target proteins during biosynthesis](https://reactome.org/content/detail/R-HSA-390471) | electronic |
| [Factors involved in megakaryocyte development and platelet production](https://reactome.org/content/detail/R-HSA-983231) | electronic |
| [Regulation of PTEN gene transcription](https://reactome.org/content/detail/R-HSA-8943724) | electronic |
| [Urea cycle](https://reactome.org/content/detail/R-HSA-70635) | other |
| [Zygotic genome activation (ZGA)](https://reactome.org/content/detail/R-HSA-9819196) | electronic |

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

**Molecular function:** transcription cis-regulatory region binding, RNA polymerase II cis-regulatory region sequence-specific DNA binding, DNA-binding transcription factor activity, RNA polymerase II-specific, cis-regulatory region sequence-specific DNA binding, core promoter sequence-specific DNA binding, TFIID-class transcription factor complex binding.

**Biological process:** negative regulation of transcription by RNA polymerase II, hematopoietic progenitor cell differentiation, nucleotide-excision repair, regulation of DNA-templated transcription, regulation of transcription by RNA polymerase II, autophagy.

## Clinical significance {#significance}

**Likely benign** — review status Expert panel *(reviewed by expert panel)*, last evaluated 2025-06-05.

**Submitter consensus:** conflicting (2 Likely benign, 1 Likely Benign, 1 Benign).

**Submission history:** 4 submissions (2017–2025); classifications have differed over time.

**ClinGen expert panel:** Likely Benign — TP53 VCEP (Li-Fraumeni syndrome). *Expert-panel curated (ACMG); the highest ClinVar review tier.*
**Applied ACMG criteria (met):** `PM2_Supporting`, `BP7`, `BP4`.
*Considered but not met:* `PM6`, `PVS1`, `PS2`, `PS3`, `PS4`, `PM1`, `PP1`, `PP2`, `PP3`, `PP4`, `BS2`, `PM3`, `BS1`, `BS4`, `BS3`, `BP5`, `BP3`, `BP1`, `BP2`, `BA1`, `PM4`.
Inheritance: Autosomal dominant inheritance.

> **Curation rationale (ClinGen, verbatim):** The c.414C>T (p.Ala138=) variant is a synonymous (silent) variant outside of the core splice motif, and BP4 code is met for splicing prediction (BP4, BP7). To our knowledge, this variant has not been reported in individuals meeting classical LFS or Chompret criteria (PS4 not met). This variant has an allele frequency of 6.195e-7 (1/1614158 alleles) across gnomAD v4.1.0 which is lower than the Clingen TP53 VCEP threshold (<0.00003) for PM2_Supporting and has no more than one allele per non-bottleneck subpopulation (PM2_Supporting). To our knowledge, functional assays have not been reported for this variant (PS3/BS3 not met). The computational splicing predictor SpliceAI gives a score of [0.01], predicting that the variant has no impact on splicing (score threshold ≤ 0.10) (BP4). In summary, this variant meets the criteria to be classified as likely benign for Li Fraumeni syndrome based on the ACMG/AMP criteria applied, as specified by the ClinGen TP53 VCEP: BP4, BP7, PM2_Supporting. (Bayesian Points: -1; VCEP specifications version 2.3)
*Source: https://cspec.clinicalgenome.org/cspec/ui/svi/affiliation/50013 · approved 2025-06-05 · [ClinGen Evidence Repository](https://erepo.genome.network/evrepo/ui/classification/0fbddfff-af44-44e7-8fc8-ba584e35fc96).*
*These are ClinGen's applied codes, reported verbatim — Sugi Variant does not re-tally or combine them into its own classification.*

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| Ambry Genetics | Likely benign | criteria provided, single submitter | clinical testing | 2017-01-27 |
| ClinGen TP53 Variant Curation Expert Panel, ClinGen | Likely Benign | reviewed by expert panel | curation | 2025-06-05 |
| Myriad Genetics, Inc. | Benign | criteria provided, single submitter | clinical testing | 2025-04-02 |
| Labcorp Genetics (formerly Invitae), Labcorp | Likely benign | criteria provided, single submitter | clinical testing | 2024-12-18 |

## Associated conditions {#conditions}

[Li-Fraumeni syndrome](https://sugi.bio/atlas/disease/li-fraumeni-syndrome/), [hereditary neoplastic syndrome](https://sugi.bio/atlas/disease/hereditary-neoplastic-syndrome/).

**Reported phenotype names (ClinVar):** Li-Fraumeni syndrome, Hereditary cancer-predisposing syndrome, Li-Fraumeni syndrome 1, Hereditary neoplastic syndrome, Neoplastic Syndromes, Hereditary, Tumor predisposition, Hereditary Cancer Syndrome, Sarcoma family syndrome of Li and Fraumeni.

## Same-residue context {#hotspot}

Residue **138** carries **2 other pathogenic ClinVar variants** — a recurrently-mutated position: [TP53 p.Ala138Pro](/variant/tp53-p-ala138pro), [TP53 p.Ala138Val](/variant/tp53-p-ala138val). *Positional co-occurrence of independent ClinVar records, not functional proof.*

## Similar variants {#similar}

Related TP53 variant pages (same residue, condition, or type): [TP53 p.Ala138Pro](/variant/tp53-p-ala138pro), [TP53 p.Ala138Val](/variant/tp53-p-ala138val), [TP53 p.Ala138Asp](/variant/tp53-p-ala138asp), [TP53 p.Ala138Gly](/variant/tp53-p-ala138gly), [TP53 p.Ala138Thr](/variant/tp53-p-ala138thr), [TP53 c.375+5G>A](/variant/tp53-c-375-plus-5g-a), [TP53 c.919+1G>A](/variant/tp53-c-919-plus-1g-a), [TP53 c.97-1G>A](/variant/tp53-c-97-minus-1g-a).

### 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 482234). 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.*