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Inheritance

1

Autosomal dominant HP:0000006

Most probands have an affected parent. The de novo proportion is unknown, and because the full phenotypic spectrum and penetrance are not established, the manifestations in a heterozygous relative cannot be predicted.

Autosomal dominant inheritance

Show evidence (3 references)

PMID:33119245 SUPPORT Human Clinical

"POT1-TPD is inherited in an autosomal dominant manner. To date, most individuals diagnosed with POT1-TPD have an affected parent; the proportion of individuals with POT1-TPD caused by a de novo pathogenic variant is unknown."

GeneReviews statement of inheritance and the unknown de novo fraction.

PMID:33119245 SUPPORT Human Clinical

"Clinical manifestations of POT1-TPD cannot be predicted in heterozygous family members because the full phenotypic spectrum and penetrance of POT1-TPD are unknown."

Records the penetrance uncertainty explicitly, so the entry does not imply a quantified risk that has not been established.

PMID:33119245 SUPPORT Human Clinical

"Each child of an individual with POT1-TPD has a 50% chance of inheriting the POT1 pathogenic variant."

The per-child transmission risk, which is the figure counselling turns on.

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Discussions and Knowledge Gaps

1

Is tumorigenesis in POT1 tumor predisposition driven by telomere elongation extending replicative capacity, or by the genomic instability that follows an uncapped telomere?

KNOWLEDGE GAP OPEN pot1_elongation_versus_instability

Attached to

pathophysiology#Telomere Fragility and Genomic Instability pathophysiology#Unrestrained Telomerase Access and Telomere Elongation

Both phenotypes are observed in POT1 variant carriers, and the literature has not resolved which one is causal. Human carrier studies report abnormally long telomeres together with increased telomere fragility, while CRISPR engineered human embryonic and hematopoietic stem cells carrying the same class of variant show consistent elongation with no detectable telomere damage response. The engineered stem cell result favours elongation as the selected property and is why the instability node on this entry is marked provisional, but it is a stem cell model rather than a tumor, so it does not close the question. The distinction matters practically: an instability driven mechanism would predict sensitivity to DNA damaging therapy that an elongation driven mechanism would not.

Show evidence (1 reference)

PMID:33934394 SUPPORT In Vitro

"Cancers with caPOT1 mutations have elongated telomeres and show increased genomic instability, but which of the two phenotypes promotes tumorigenesis is unclear."

The authors state the open question directly, which is what this discussion records rather than resolving.

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Pathophysiology

5

POT1 Loss of Function

Heterozygous germline variants throughout the POT1 reading frame, most commonly missense and nonsense changes. They act either by disrupting the oligonucleotide binding folds that contact the single stranded telomeric overhang, or by disrupting the interface between POT1 and its shelterin partner ACD/TPP1.

Genetic context variant_origin: GERMLINE zygosity: HETEROZYGOUS functional_impact_category: LOSS_OF_FUNCTION

Heterozygous germline missense, nonsense, frameshift, and splice site variants distributed across the POT1 reading frame, converging on loss of telomeric single stranded DNA binding or loss of the POT1 to ACD interaction.

single-stranded telomeric DNA binding GO:0043047 ⇓ LOSS OF FUNCTION

Downstream

Defective Shelterin Capping of the Telomeric Overhang

Show evidence (2 references)

PMID:33934394 SUPPORT In Vitro

"These cancer-associated POT1 (caPOT1) mutations are generally heterozygous, missense, or nonsense mutations occurring throughout the POT1 reading frame."

Characterizes the germline allele classes and their distribution across the gene.

PMID:27528712 SUPPORT Human Clinical

"We performed whole-exome sequencing of 66 CLL families, identifying 4 families where loss-of-function mutations in protection of telomeres 1 (POT1) co-segregated with CLL."

Establishes cosegregation of POT1 loss-of-function alleles with familial disease.

Defective Shelterin Capping of the Telomeric Overhang

Less POT1 is bound at the telomere, so the single stranded 3' overhang is incompletely capped by shelterin. Carriers show reduced telomere bound POT1 directly, not merely a predicted structural defect.

telomere capping GO:0016233 ↓ DECREASED

Downstream

Unrestrained Telomerase Access and Telomere Elongation

Telomere Fragility and Genomic Instability

Show evidence (1 reference)

PMID:26403419 SUPPORT Human Clinical

"Functional and in vitro studies demonstrate that carriers of the mutation show reduced telomere-bound POT1 levels, abnormally long telomeres and increased telomere fragility."

Measures reduced telomere-bound POT1 in human carriers, establishing the capping defect rather than inferring it from structure alone.

Unrestrained Telomerase Access and Telomere Elongation

POT1 normally limits telomerase access to the 3' overhang. Losing that restraint lets telomerase extend the telomere, so POT1-TPD telomeres are abnormally long. This is the mechanistic inversion that separates this syndrome from the short telomere biology disorders.

negative regulation of telomere maintenance via telomerase GO:0032211 ↓ DECREASED

Animal models

Pot1a R117C knock-in mouse Mouse recapitulates Heterozygous knock-in fibroblasts and tissues carry longer telomeres than wild type, and the elongation disappears on a telomerase-null background, which is direct evidence that the mechanism runs through telomerase access rather than through some other route to long telomeres.

Downstream

Extended Replicative Capacity of Incipient Cancer Cells

Show evidence (2 references)

PMID:33934394 SUPPORT In Vitro

"Furthermore, hESC lines with caPOT1 mutations showed no detectable telomere damage response while showing consistent telomere elongation."

Engineered human stem cell lines show consistent elongation, isolating elongation as a direct and reproducible consequence of the POT1 lesion.

PMID:38839987 SUPPORT Human Clinical

"Some POT1 gene pathogenic variants (PV) lead to telomere elongation, genomic instability and higher risk of cancer."

States the elongation phenotype and its link to cancer risk in the clinical literature.

Telomere Fragility and Genomic Instability

Mechanism confidence: Provisional

An uncapped overhang also leaves the telomere structurally fragile, and tumors carrying POT1 variants show increased genomic instability. Whether this or the elongation is what actually drives tumorigenesis is not settled; see the discussion recorded on this entry.

Downstream

Extended Replicative Capacity of Incipient Cancer Cells

Show evidence (2 references)

PMID:26403419 SUPPORT Human Clinical

"Functional and in vitro studies demonstrate that carriers of the mutation show reduced telomere-bound POT1 levels, abnormally long telomeres and increased telomere fragility."

Documents increased telomere fragility alongside the elongation in human carriers.

PMID:33934394 REFUTE In Vitro

"HSCs with caPOT1 mutations did not show overt telomere damage."

Argues against a damage-driven mechanism in the relevant stem cell compartment, which is why this node is marked provisional rather than established.

Extended Replicative Capacity of Incipient Cancer Cells

Longer telomeres postpone replicative senescence, so a cell that has acquired an initiating oncogenic lesion can keep dividing and accumulate further hits. This is the currently favoured account of why POT1 variants are selected for during cancer progression.

melanocyte CL:0000148 endothelial cell CL:0000115 B cell CL:0000236 glial cell CL:0000125

replicative senescence GO:0090399 ↓ DECREASED

Downstream

Cutaneous Melanoma

Angiosarcoma

Glioma

Chronic Lymphatic Leukemia

Thyroid Carcinoma Part of the expanding rather than the established spectrum; the edge is drawn because the same telomere mechanism is the only one proposed for it.

Show evidence (1 reference)

PMID:33934394 SUPPORT In Vitro

"Thus, caPOT1 mutations are likely selected for during cancer progression because of their ability to elongate telomeres and extend the proliferative capacity of the incipient cancer cells."

The authors' conclusion naming extended proliferative capacity as the selected advantage, quoted with its "likely" hedge intact.

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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

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Phenotypes

5

Blood 1

Chronic Lymphatic Leukemia OCCASIONAL HP:0005550

Show evidence (1 reference)

PMID:27528712 SUPPORT Human Clinical

"In a complementary analysis of 1083 cases and 5854 controls, the POT1 p.Gln376Arg variant, which has a global minor allele frequency of 0.0005, conferred a 3.61-fold increased risk of CLL (P = .009)."

Quantifies the CLL risk conferred by a specific POT1 allele in a case-control analysis.

Endocrine 1

Thyroid Carcinoma VERY_RARE HP:0002890

Show evidence (1 reference)

PMID:38839987 SUPPORT Human Clinical

"POT1-TPD was observed, but also a higher incidence of other cancers (other sarcomas, papillary thyroid cancer, early onset prostate cancer and leukaemia)."

Reports the additional malignancies seen in three extended pedigrees, which is the basis for treating thyroid cancer as an emerging rather than established association.

Integument 1

Cutaneous Melanoma FREQUENT HP:0012056

Show evidence (2 references)

PMID:33119245 SUPPORT Human Clinical

"POT1 tumor predisposition (POT1-TPD) is characterized by an increased lifetime risk for multiple cutaneous melanomas, sarcomas (particularly cardiac angiosarcomas), chronic lymphocytic leukemia (CLL), and gliomas."

GeneReviews statement of the core tumor spectrum.

PMID:33119245 SUPPORT Human Clinical

"The age of onset for first primary cutaneous melanoma ranges from 15 to 80 years."

Gives the observed age range, which is what the surveillance start age is set against.

Neoplasm 2

Angiosarcoma OCCASIONAL HP:0200058

Show evidence (2 references)

PMID:26403419 SUPPORT Human Clinical

"Here we show, by whole-exome sequencing of a TP53-negative Li-Fraumeni-like (LFL) family including CAS cases, that a missense variant (p.R117C) in POT1 (protection of telomeres 1) gene is responsible for CAS."

The gene-disease discovery study, linking POT1 to cardiac angiosarcoma.

PMID:26403419 SUPPORT Human Clinical

"The same gene alteration is found in two other LFL families with CAS, supporting the causal effect of the identified mutation."

Independent family replication supporting causality rather than a single-family finding.

Glioma OCCASIONAL HP:0009733

Show evidence (1 reference)

PMID:38839987 SUPPORT Human Clinical

"It is associated with increased risk of cutaneous melanoma, chronic lymphocytic leukaemia, angiosarcoma and gliomas."

Names glioma among the established POT1-TPD tumor types.

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Genetic Associations

1

POT1 (Heterozygous germline loss of function variants in POT1 cause POT1 tumor predisposition syndrome.)

Gene: POT1 hgnc:17284 relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (3 references)

PMID:27528712 SUPPORT Human Clinical

"The c.1164-1G>A splice-site, p.Gln358SerfsTer13 frameshift, and p.Gln376Arg missense mutations are likely to impact the interaction between POT1 and adrenocortical dysplasia homolog (ACD), which is a part of the telomere-capping shelterin complex."

Defines the second mechanistic class of alleles, those acting through the ACD interface.

PMID:27528712 SUPPORT Human Clinical

"We also identified mutations in ACD (c.752-2A>C) and another shelterin component, telomeric repeat binding factor 2, interacting protein (p.Ala104Pro and p.Arg133Gln), in 3 CLL families."

Supports the note that other shelterin genes produce comparable familial disease, which matters when POT1 sequencing is negative.

PMID:26403419 SUPPORT Human Clinical

"The mutation is recently found once in 121,324 studied alleles in ExAC server but it is not described in any other database or found in 1,520 Spanish controls."

Establishes the rarity of the discovery allele in population and control datasets.

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Medical Actions

4

Melanoma Surveillance

Action: Cancer Screening NCIT:C15406

Full skin examination by a dermatologist from age 18 years at least six monthly, with excision of suspicious lesions, intensified to three monthly for those with multiple atypical nevi or a melanoma history. Monthly self examination is encouraged alongside it.

Mechanism Target:

Cutaneous Melanoma

Show evidence (1 reference)

PMID:33119245 SUPPORT Human Clinical

"Full skin examination by a dermatologist beginning at age 18 years at least every six months with excision of any lesions suspicious for melanoma"

The GeneReviews dermatologic surveillance recommendation.

Whole-Body MRI and Hematologic Surveillance

Action: Cancer Screening NCIT:C15406

Annual whole body MRI from age 18 years for non-cutaneous, non-brain malignancies, annual complete blood count with differential to screen for chronic lymphocytic leukemia, and brain MRI every one to two years depending on the family history of glioma.

Mechanism Target:

Chronic Lymphatic Leukemia

Angiosarcoma

Glioma

Show evidence (2 references)

PMID:33119245 SUPPORT Human Clinical

"Annual whole-body MRI beginning at age 18 years, or earlier depending on personal and family history of non-cutaneous, non-brain malignancies."

The GeneReviews whole-body imaging recommendation and its age trigger.

PMID:33119245 SUPPORT Human Clinical

"Annual complete blood count with differential beginning at age 18 years to screen for CLL."

The GeneReviews hematologic surveillance recommendation.

Avoidance of Ultraviolet and Ionizing Radiation Exposure

Action: Supportive Care NCIT:C15747

Tanning beds and unprotected sun exposure are to be avoided, as is radiation in diagnostic procedures. The radiation caution is why the imaging surveillance above is built on MRI rather than CT.

Mechanism Target:

Cutaneous Melanoma

Show evidence (2 references)

PMID:33119245 SUPPORT Human Clinical

"Agents/circumstances to avoid: Tanning bed use and unprotected sun exposure; radiation in diagnostic procedures."

The GeneReviews agents and circumstances to avoid statement.

PMID:38254993 SUPPORT Human Clinical

"Furthermore, a proposal of a surveillance protocol related to the cancers associated with POT1 pathogenic variants requires reliable data to avoid an excessive, possibly unjustified, burden for POT1 variant carriers."

Records the argument against applying maximal Li-Fraumeni-style surveillance to every carrier by default, which is a live caveat on the protocol above rather than a reason to omit it.

Cascade Genetic Testing of First-Degree Relatives

Action: Genetic Testing NCIT:C15709

Targeted testing for the familial POT1 variant in first-degree relatives. This is the step that moves a relative from unknown risk into the surveillance protocol, which is why it is modeled as an intervention rather than left in counselling prose. GeneReviews does not generally recommend it below age 18, since the associated cancers are predominantly adult onset, unless the family history includes early cancers.

Show evidence (2 references)

PMID:33119245 SUPPORT Human Clinical

"Molecular genetic testing for the familial POT1 pathogenic variant should be offered to first-degree relatives to identify those who would benefit from early surveillance and intervention."

The GeneReviews recommendation for testing at-risk relatives.

PMID:33119245 SUPPORT Human Clinical

"Although molecular genetic testing for POT1-TPD is generally not recommended for at-risk individuals younger than age 18 years, a history of early cancers in the family may warrant predictive testing prior to age 18 years."

Records the age threshold and its exception, which is the part that matters in a pediatric setting.

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Diagnosis

1

Molecular confirmation of POT1-TPD

The diagnosis rests on finding a heterozygous germline POT1 pathogenic variant in someone with suggestive findings. It is worth stating what does not make the diagnosis: although the entire mechanism of this syndrome is telomere length, measuring telomere length is not a diagnostic test for it, and the strength of the evidence tying POT1 to cancers outside melanoma is itself contested.

Genetic Testing NCIT:C15709

Show evidence (2 references)

PMID:33119245 SUPPORT Human Clinical

"The diagnosis of POT1-TPD is established in a proband with suggestive findings and a heterozygous germline pathogenic variant in POT1 identified by molecular genetic testing."

The GeneReviews statement of how the diagnosis is established.

PMID:38254993 SUPPORT Human Clinical

"While the key role, and related risks, of the alterations in POT1 in melanoma are established, the correlation between germline POT1 variants and the susceptibility to other cancers partially lacks evidence, due also to the rarity of POT1-TPD."

Calibrates how far a molecular diagnosis licenses a non-melanoma cancer risk estimate, which bears directly on what the diagnosis means for a carrier.

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Differential Diagnoses

4

Conditions with similar clinical presentations that must be differentiated from POT1 Tumor Predisposition Syndrome:

Li-Fraumeni syndrome MONDO:0018875

Overlapping Features The clinical starting point for most POT1-TPD diagnoses. POT1-TPD was identified by sequencing TP53-negative Li-Fraumeni-like families, and it remains the syndrome to consider when such a pedigree, particularly one containing angiosarcoma, has no TP53 variant.

Distinguishing Features

A TP53 pathogenic variant establishes Li-Fraumeni syndrome; POT1 tumor predisposition is found in TP53-negative Li-Fraumeni-like pedigrees.
Cardiac angiosarcoma with multiple cutaneous melanomas favors POT1 tumor predisposition.
Childhood adrenocortical carcinoma, choroid plexus carcinoma, and early osteosarcoma favor Li-Fraumeni syndrome; POT1-associated cancers are predominantly adult onset.

Show evidence (1 reference)

PMID:26403419 SUPPORT Human Clinical

"We extend the analysis to TP53-negative LFL families with no CAS and find the same mutation in a breast AS family."

Documents the TP53-negative Li-Fraumeni-like ascertainment route through which this syndrome is found.

BAP1 tumor predisposition syndrome Not Yet Curated MONDO:0013692

Overlapping Features The other tumor predisposition syndrome that presents through melanocytic lesions and is weighed alongside POT1 in a melanoma genetics clinic. BAP1 carriers develop uveal melanoma, mesothelioma, renal cell carcinoma and characteristic melanocytic tumors, a spectrum that overlaps POT1 only at cutaneous melanoma.

Distinguishing Features

Uveal melanoma, mesothelioma or renal cell carcinoma favors BAP1-related tumor predisposition.
Cardiac angiosarcoma, glioma or chronic lymphocytic leukemia favors POT1 tumor predisposition.

Show evidence (1 reference)

PMID:38254993 SUPPORT Human Clinical

"The Protection of Telomere 1 (POT1) gene was identified as a melanoma predisposition candidate nearly 10 years ago."

Establishes melanoma predisposition as the entry point through which POT1 is considered, which is the setting in which this differential arises.

Familial melanoma Not Yet Curated MONDO:0018961

Overlapping Features CDKN2A and CDK4 account for most of the familial melanoma that has an identified cause, and POT1 was found by sequencing families that were negative for them. A POT1 diagnosis is therefore usually reached after these are excluded.

Distinguishing Features

A CDKN2A or CDK4 pathogenic variant establishes the more common cause of familial melanoma.
Melanoma alongside cardiac angiosarcoma, glioma or chronic lymphocytic leukemia favors POT1 tumor predisposition.

Show evidence (1 reference)

PMID:38254993 SUPPORT Human Clinical

"While the key role, and related risks, of the alterations in POT1 in melanoma are established, the correlation between germline POT1 variants and the susceptibility to other cancers partially lacks evidence, due also to the rarity of POT1-TPD."

Confirms melanoma as the established POT1 association, which is what places this syndrome in the familial melanoma differential in the first place.

Dyskeratosis congenita MONDO:0015780

Overlapping Features The mechanistic mirror image. Dyskeratosis congenita is a short telomere syndrome presenting with bone marrow failure, mucocutaneous findings, and pulmonary fibrosis; POT1 tumor predisposition is a long telomere syndrome presenting with solid tumors and leukemia, without the marrow failure phenotype.

Distinguishing Features

Short telomeres with bone marrow failure and pulmonary fibrosis favor dyskeratosis congenita.
Abnormally long telomeres with melanoma, angiosarcoma, glioma, or chronic lymphocytic leukemia favor POT1 tumor predisposition.

Show evidence (1 reference)

PMID:38839987 SUPPORT Human Clinical

"Protection of Telomeres Protein 1 (POT1) protein is an essential subunit of the shelterin telomere binding complex, regulating telomere length."

Places POT1 in the shelterin complex shared with the telomere biology disorders, which is what makes this a mechanistic differential rather than a clinical one.

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Animal Models

1

Pot1a R117C knock-in mouse

The discovery allele from the human cardiac angiosarcoma families, knocked into the endogenous Pot1a locus in the heterozygous state that matches the human syndrome. It is the model that ties this entry's three central claims together: telomere elongation, telomerase dependence of that elongation, and dominant-negative action of the allele.

Species

Mouse

Genotype

Pot1a p.R117C knock-in, heterozygous (Pot1a+/ki)

Publication

PMID:35727838

Pathograph links

Unrestrained Telomerase Access and Telomere Elongation recapitulates fidelity: moderate Heterozygous knock-in fibroblasts and tissues carry longer telomeres than wild type, and the elongation disappears on a telomerase-null background, which is direct evidence that the mechanism runs through telomerase access rather than through some other route to long telomeres.

Limitations: Mice carry two paralogues, Pot1a and Pot1b, which split the functions of the single human POT1 protein, so the mapping from mouse Pot1a to human POT1 is not one to one and quantitative extrapolation is bounded.

Readouts

Telomere length in MEFs and tissues

Direction: INCREASED

Interpretation: Elongation is the measured correlate of the lost shelterin brake.

Show evidence (1 reference)

PMID:35727838 SUPPORT Model Organism

"We find here that both mouse embryonic fibroblasts (MEFs) and tissues from Pot1a+/ki mice show longer telomeres than wild-type controls."

The telomere-length measurement in the knock-in model.

Telomerase dependence of the elongation

Direction: ABOLISHED

Interpretation: Removing telomerase abolishes the elongation, establishing that the long telomeres are made by telomerase rather than by an alternative pathway. Note this readout is measured in Pot1a+/ki Tert-/- double mutant fibroblasts rather than in the Pot1a+/ki genotype this model entry declares; the comparison is the point of the experiment.

Show evidence (1 reference)

PMID:35727838 SUPPORT Model Organism

"Longer telomeres in Pot1a+/ki MEFs are dependent on telomerase activity as they are not found in double mutant Pot1a+/ki Tert-/- telomerase-deficient MEFs."

The telomerase-null epistasis result behind the dependence claim.

Show evidence (1 reference)

PMID:35727838 SUPPORT Model Organism

"By using complementation assays we further show that POT1a pR117C exerts dominant-negative effects at telomeres."

Supports treating this model as informative for the elongation node by establishing that the allele acts dominant-negatively, as assumed for the human heterozygous state.

{ }

Source YAML

click to show

name: POT1 Tumor Predisposition Syndrome
creation_date: "2026-09-01T00:00:00Z"
category: Mendelian
categories:
- Hereditary Cancer Syndrome
- Cancer Predisposition Syndrome
- Telomere Biology Disorder
parents:
- hereditary cancer-predisposing syndrome
disease_term:
  preferred_term: POT1 tumor predisposition
  term:
    id: MONDO:0014368
    label: tumor predisposition syndrome 3
synonyms:
- POT1-TPD
- POT1-related tumor predisposition syndrome
- POT1 tumor predisposition
- tumor predisposition syndrome 3
- melanoma, cutaneous malignant, susceptibility to, 10
- glioma susceptibility type 9
description: >-
  POT1 tumor predisposition is an autosomal dominant cancer predisposition syndrome
  caused by heterozygous germline loss of function variants in POT1, the
  single stranded DNA binding component of the shelterin complex that caps the
  telomeric 3' overhang. The characteristic tumor spectrum is cutaneous melanoma,
  often multiple, together with angiosarcoma (notably cardiac angiosarcoma), glioma,
  and chronic lymphocytic leukemia.
  Two things make this entry unusual among the hereditary cancer syndromes. The
  first is the direction of the telomere defect. Most inherited telomere biology
  disorders are short telomere syndromes; here the loss of POT1 removes a brake on
  telomerase access to the overhang, so telomeres become abnormally long. POT1-TPD
  is the long telomere counterpart of dyskeratosis congenita, and the marrow failure
  and pulmonary fibrosis of the short telomere disorders are absent.
  One reading caution about this entry. Penetrance for POT1-TPD is not established,
  and the frequency values on the tumor phenotypes below are therefore a curator
  assigned ordering of the spectrum rather than measured rates. They encode how
  consistently each tumor appears in the reported spectrum, with melanoma the most
  consistent and thyroid carcinoma part of the emerging rather than established
  association. Do not read them as risk estimates.
  The second is that it is defined against a negative. The syndrome was found by
  sequencing TP53-negative Li-Fraumeni-like families, and it remains the diagnosis
  to consider when a Li-Fraumeni-like pedigree, especially one containing
  angiosarcoma, has no TP53 variant. Penetrance is not established, and most
  associated cancers present in adulthood, which is why predictive testing is not
  routinely offered in childhood.
inheritance:
- name: Autosomal dominant
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  description: >-
    Most probands have an affected parent. The de novo proportion is unknown, and
    because the full phenotypic spectrum and penetrance are not established, the
    manifestations in a heterozygous relative cannot be predicted.
  evidence:
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "POT1-TPD is inherited in an autosomal dominant manner. To date, most individuals diagnosed with POT1-TPD have an affected parent; the proportion of individuals with POT1-TPD caused by a de novo pathogenic variant is unknown."
    explanation: GeneReviews statement of inheritance and the unknown de novo fraction.
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Clinical manifestations of POT1-TPD cannot be predicted in heterozygous family members because the full phenotypic spectrum and penetrance of POT1-TPD are unknown."
    explanation: >-
      Records the penetrance uncertainty explicitly, so the entry does not imply a
      quantified risk that has not been established.
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Each child of an individual with POT1-TPD has a 50% chance of inheriting the POT1 pathogenic variant."
    explanation: The per-child transmission risk, which is the figure counselling turns on.
pathophysiology:
- name: POT1 Loss of Function
  biological_scale: MOLECULAR
  description: >-
    Heterozygous germline variants throughout the POT1 reading frame, most commonly
    missense and nonsense changes. They act either by disrupting the
    oligonucleotide binding folds that contact the single stranded telomeric
    overhang, or by disrupting the interface between POT1 and its shelterin partner
    ACD/TPP1.
  genetic_context:
    variant_origin: GERMLINE
    zygosity: HETEROZYGOUS
    functional_impact_category: LOSS_OF_FUNCTION
    description: >-
      Heterozygous germline missense, nonsense, frameshift, and splice site variants
      distributed across the POT1 reading frame, converging on loss of telomeric
      single stranded DNA binding or loss of the POT1 to ACD interaction.
  molecular_functions:
  - preferred_term: single-stranded telomeric DNA binding
    term:
      id: GO:0043047
      label: single-stranded telomeric DNA binding
    modifier: LOSS_OF_FUNCTION
  downstream:
  - target: Defective Shelterin Capping of the Telomeric Overhang
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:27528712
      reference_title: "Germ line mutations in shelterin complex genes are associated with familial chronic lymphocytic leukemia."
      supports: SUPPORT
      evidence_source: COMPUTATIONAL
      snippet: "The p.Tyr36Cys mutation is predicted to disrupt the interaction between POT1 and the telomeric overhang."
      explanation: >-
        Connects a specific germline allele to loss of the POT1 to overhang interaction,
        which is the step this edge asserts.
  evidence:
  - reference: PMID:33934394
    reference_title: "Cancer-associated POT1 mutations lead to telomere elongation without induction of a DNA damage response."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "These cancer-associated POT1 (caPOT1) mutations are generally heterozygous, missense, or nonsense mutations occurring throughout the POT1 reading frame."
    explanation: Characterizes the germline allele classes and their distribution across the gene.
  - reference: PMID:27528712
    reference_title: "Germ line mutations in shelterin complex genes are associated with familial chronic lymphocytic leukemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We performed whole-exome sequencing of 66 CLL families, identifying 4 families where loss-of-function mutations in protection of telomeres 1 (POT1) co-segregated with CLL."
    explanation: Establishes cosegregation of POT1 loss-of-function alleles with familial disease.
- name: Defective Shelterin Capping of the Telomeric Overhang
  biological_scale: MOLECULAR
  description: >-
    Less POT1 is bound at the telomere, so the single stranded 3' overhang is
    incompletely capped by shelterin. Carriers show reduced telomere bound POT1
    directly, not merely a predicted structural defect.
  biological_processes:
  - preferred_term: telomere capping
    term:
      id: GO:0016233
      label: telomere capping
    modifier: DECREASED
  downstream:
  - target: Unrestrained Telomerase Access and Telomere Elongation
    causal_link_type: DIRECT
  - target: Telomere Fragility and Genomic Instability
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:26403419
    reference_title: "A mutation in the POT1 gene is responsible for cardiac angiosarcoma in TP53-negative Li-Fraumeni-like families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Functional and in vitro studies demonstrate that carriers of the mutation show reduced telomere-bound POT1 levels, abnormally long telomeres and increased telomere fragility."
    explanation: >-
      Measures reduced telomere-bound POT1 in human carriers, establishing the capping
      defect rather than inferring it from structure alone.
- name: Unrestrained Telomerase Access and Telomere Elongation
  biological_scale: CELLULAR
  description: >-
    POT1 normally limits telomerase access to the 3' overhang. Losing that restraint
    lets telomerase extend the telomere, so POT1-TPD telomeres are abnormally long.
    This is the mechanistic inversion that separates this syndrome from the short
    telomere biology disorders.
  biological_processes:
  - preferred_term: negative regulation of telomere maintenance via telomerase
    term:
      id: GO:0032211
      label: negative regulation of telomere maintenance via telomerase
    modifier: DECREASED
  downstream:
  - target: Extended Replicative Capacity of Incipient Cancer Cells
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:33934394
    reference_title: "Cancer-associated POT1 mutations lead to telomere elongation without induction of a DNA damage response."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Furthermore, hESC lines with caPOT1 mutations showed no detectable telomere damage response while showing consistent telomere elongation."
    explanation: >-
      Engineered human stem cell lines show consistent elongation, isolating elongation as
      a direct and reproducible consequence of the POT1 lesion.
  - reference: PMID:38839987
    reference_title: "POT1 tumour predisposition: a broader spectrum of associated malignancies and proposal for additional screening program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Some POT1 gene pathogenic variants (PV) lead to telomere elongation, genomic instability and higher risk of cancer."
    explanation: States the elongation phenotype and its link to cancer risk in the clinical literature.
- name: Telomere Fragility and Genomic Instability
  biological_scale: CELLULAR
  description: >-
    An uncapped overhang also leaves the telomere structurally fragile, and tumors
    carrying POT1 variants show increased genomic instability. Whether this or the
    elongation is what actually drives tumorigenesis is not settled; see the
    discussion recorded on this entry.
  mechanism_confidence: PROVISIONAL
  downstream:
  - target: Extended Replicative Capacity of Incipient Cancer Cells
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  evidence:
  - reference: PMID:26403419
    reference_title: "A mutation in the POT1 gene is responsible for cardiac angiosarcoma in TP53-negative Li-Fraumeni-like families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Functional and in vitro studies demonstrate that carriers of the mutation show reduced telomere-bound POT1 levels, abnormally long telomeres and increased telomere fragility."
    explanation: Documents increased telomere fragility alongside the elongation in human carriers.
  - reference: PMID:33934394
    reference_title: "Cancer-associated POT1 mutations lead to telomere elongation without induction of a DNA damage response."
    supports: REFUTE
    evidence_source: IN_VITRO
    snippet: "HSCs with caPOT1 mutations did not show overt telomere damage."
    explanation: >-
      Argues against a damage-driven mechanism in the relevant stem cell compartment,
      which is why this node is marked provisional rather than established.
- name: Extended Replicative Capacity of Incipient Cancer Cells
  biological_scale: CELLULAR
  description: >-
    Longer telomeres postpone replicative senescence, so a cell that has acquired an
    initiating oncogenic lesion can keep dividing and accumulate further hits. This
    is the currently favoured account of why POT1 variants are selected for during
    cancer progression.
  biological_processes:
  - preferred_term: replicative senescence
    term:
      id: GO:0090399
      label: replicative senescence
    modifier: DECREASED
  cell_types:
  - preferred_term: melanocyte
    term:
      id: CL:0000148
      label: melanocyte
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  - preferred_term: B cell
    term:
      id: CL:0000236
      label: B cell
  - preferred_term: glial cell
    term:
      id: CL:0000125
      label: glial cell
  downstream:
  - target: Cutaneous Melanoma
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Angiosarcoma
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Glioma
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Chronic Lymphatic Leukemia
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Thyroid Carcinoma
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Part of the expanding rather than the established spectrum; the edge is drawn
      because the same telomere mechanism is the only one proposed for it.
  evidence:
  - reference: PMID:33934394
    reference_title: "Cancer-associated POT1 mutations lead to telomere elongation without induction of a DNA damage response."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Thus, caPOT1 mutations are likely selected for during cancer progression because of their ability to elongate telomeres and extend the proliferative capacity of the incipient cancer cells."
    explanation: >-
      The authors' conclusion naming extended proliferative capacity as the selected
      advantage, quoted with its "likely" hedge intact.
phenotypes:
- category: Neoplastic
  name: Cutaneous Melanoma
  description: >-
    Often multiple primary melanomas. Onset spans a wide age range, from the second
    decade onward.
  phenotype_term:
    preferred_term: Cutaneous melanoma
    term:
      id: HP:0012056
      label: Cutaneous melanoma
  frequency: FREQUENT
  evidence:
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "POT1 tumor predisposition (POT1-TPD) is characterized by an increased lifetime risk for multiple cutaneous melanomas, sarcomas (particularly cardiac angiosarcomas), chronic lymphocytic leukemia (CLL), and gliomas."
    explanation: GeneReviews statement of the core tumor spectrum.
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The age of onset for first primary cutaneous melanoma ranges from 15 to 80 years."
    explanation: Gives the observed age range, which is what the surveillance start age is set against.
- category: Neoplastic
  name: Angiosarcoma
  description: >-
    Cardiac angiosarcoma is the characteristic sarcoma, and was the phenotype through
    which the syndrome was originally identified in TP53-negative Li-Fraumeni-like
    families.
  phenotype_term:
    preferred_term: Angiosarcoma
    term:
      id: HP:0200058
      label: Angiosarcoma
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:26403419
    reference_title: "A mutation in the POT1 gene is responsible for cardiac angiosarcoma in TP53-negative Li-Fraumeni-like families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Here we show, by whole-exome sequencing of a TP53-negative Li-Fraumeni-like (LFL) family including CAS cases, that a missense variant (p.R117C) in POT1 (protection of telomeres 1) gene is responsible for CAS."
    explanation: The gene-disease discovery study, linking POT1 to cardiac angiosarcoma.
  - reference: PMID:26403419
    reference_title: "A mutation in the POT1 gene is responsible for cardiac angiosarcoma in TP53-negative Li-Fraumeni-like families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The same gene alteration is found in two other LFL families with CAS, supporting the causal effect of the identified mutation."
    explanation: Independent family replication supporting causality rather than a single-family finding.
- category: Neoplastic
  name: Glioma
  phenotype_term:
    preferred_term: Glioma
    term:
      id: HP:0009733
      label: Glioma
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:38839987
    reference_title: "POT1 tumour predisposition: a broader spectrum of associated malignancies and proposal for additional screening program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It is associated with increased risk of cutaneous melanoma, chronic lymphocytic leukaemia, angiosarcoma and gliomas."
    explanation: Names glioma among the established POT1-TPD tumor types.
- category: Neoplastic
  name: Chronic Lymphatic Leukemia
  phenotype_term:
    preferred_term: Chronic lymphatic leukemia
    term:
      id: HP:0005550
      label: Chronic lymphatic leukemia
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:27528712
    reference_title: "Germ line mutations in shelterin complex genes are associated with familial chronic lymphocytic leukemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In a complementary analysis of 1083 cases and 5854 controls, the POT1 p.Gln376Arg variant, which has a global minor allele frequency of 0.0005, conferred a 3.61-fold increased risk of CLL (P = .009)."
    explanation: Quantifies the CLL risk conferred by a specific POT1 allele in a case-control analysis.
- category: Neoplastic
  name: Thyroid Carcinoma
  description: >-
    Reported in the broader phenotype described by extended-pedigree studies, as
    papillary thyroid cancer. Part of the expanding rather than the established
    spectrum.
  phenotype_term:
    preferred_term: Thyroid carcinoma
    term:
      id: HP:0002890
      label: Thyroid carcinoma
  frequency: VERY_RARE
  evidence:
  - reference: PMID:38839987
    reference_title: "POT1 tumour predisposition: a broader spectrum of associated malignancies and proposal for additional screening program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "POT1-TPD was observed, but also a higher incidence of other cancers (other sarcomas, papillary thyroid cancer, early onset prostate cancer and leukaemia)."
    explanation: >-
      Reports the additional malignancies seen in three extended pedigrees, which is the
      basis for treating thyroid cancer as an emerging rather than established association.
diagnosis:
- name: Molecular confirmation of POT1-TPD
  diagnosis_term:
    preferred_term: Genetic Testing
    term:
      id: NCIT:C15709
      label: Genetic Testing
  description: >-
    The diagnosis rests on finding a heterozygous germline POT1 pathogenic variant in
    someone with suggestive findings. It is worth stating what does not make the
    diagnosis: although the entire mechanism of this syndrome is telomere length,
    measuring telomere length is not a diagnostic test for it, and the strength of the
    evidence tying POT1 to cancers outside melanoma is itself contested.
  evidence:
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The diagnosis of POT1-TPD is established in a proband with suggestive findings and a heterozygous germline pathogenic variant in POT1 identified by molecular genetic testing."
    explanation: The GeneReviews statement of how the diagnosis is established.
  - reference: PMID:38254993
    reference_title: "Germline POT1 Variants: A Critical Perspective on POT1 Tumor Predisposition Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "While the key role, and related risks, of the alterations in POT1 in melanoma are established, the correlation between germline POT1 variants and the susceptibility to other cancers partially lacks evidence, due also to the rarity of POT1-TPD."
    explanation: >-
      Calibrates how far a molecular diagnosis licenses a non-melanoma cancer risk
      estimate, which bears directly on what the diagnosis means for a carrier.
animal_models:
- name: Pot1a R117C knock-in mouse
  species: Mouse
  genotype: Pot1a p.R117C knock-in, heterozygous (Pot1a+/ki)
  publication: PMID:35727838
  description: >-
    The discovery allele from the human cardiac angiosarcoma families, knocked into the
    endogenous Pot1a locus in the heterozygous state that matches the human syndrome.
    It is the model that ties this entry's three central claims together: telomere
    elongation, telomerase dependence of that elongation, and dominant-negative action
    of the allele.
  modeled_mechanisms:
  - target: Unrestrained Telomerase Access and Telomere Elongation
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Heterozygous knock-in fibroblasts and tissues carry longer telomeres than wild
      type, and the elongation disappears on a telomerase-null background, which is
      direct evidence that the mechanism runs through telomerase access rather than
      through some other route to long telomeres.
    limitations: >-
      Mice carry two paralogues, Pot1a and Pot1b, which split the functions of the
      single human POT1 protein, so the mapping from mouse Pot1a to human POT1 is not
      one to one and quantitative extrapolation is bounded.
    readouts:
    - name: Telomere length in MEFs and tissues
      target: Unrestrained Telomerase Access and Telomere Elongation
      direction: INCREASED
      interpretation: Elongation is the measured correlate of the lost shelterin brake.
      evidence:
      - reference: PMID:35727838
        reference_title: "A mouse model for Li-Fraumeni-Like Syndrome with cardiac angiosarcomas associated to POT1 mutations."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "We find here that both mouse embryonic fibroblasts (MEFs) and tissues from Pot1a+/ki mice show longer telomeres than wild-type controls."
        explanation: The telomere-length measurement in the knock-in model.
    - name: Telomerase dependence of the elongation
      target: Unrestrained Telomerase Access and Telomere Elongation
      direction: ABOLISHED
      interpretation: >-
        Removing telomerase abolishes the elongation, establishing that the long
        telomeres are made by telomerase rather than by an alternative pathway. Note
        this readout is measured in Pot1a+/ki Tert-/- double mutant fibroblasts rather
        than in the Pot1a+/ki genotype this model entry declares; the comparison is the
        point of the experiment.
      evidence:
      - reference: PMID:35727838
        reference_title: "A mouse model for Li-Fraumeni-Like Syndrome with cardiac angiosarcomas associated to POT1 mutations."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "Longer telomeres in Pot1a+/ki MEFs are dependent on telomerase activity as they are not found in double mutant Pot1a+/ki Tert-/- telomerase-deficient MEFs."
        explanation: The telomerase-null epistasis result behind the dependence claim.
    evidence:
    - reference: PMID:35727838
      reference_title: "A mouse model for Li-Fraumeni-Like Syndrome with cardiac angiosarcomas associated to POT1 mutations."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "By using complementation assays we further show that POT1a pR117C exerts dominant-negative effects at telomeres."
      explanation: >-
        Supports treating this model as informative for the elongation node by
        establishing that the allele acts dominant-negatively, as assumed for the human
        heterozygous state.
  - target: Angiosarcoma
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Heterozygous mice spontaneously develop angiosarcomas including cardiac
      angiosarcomas, reproducing the defining tumor of the human families from which
      this allele came, with long telomeres localized to endothelial cells.
    limitations: >-
      The model reproduces the angiosarcoma arm of the spectrum; melanoma, glioma and
      chronic lymphocytic leukemia are not reported in it, so it does not speak to the
      rest of the human tumor spectrum.
    readouts:
    - name: Spontaneous angiosarcoma incidence
      target: Angiosarcoma
      direction: INCREASED
      interpretation: Tumor incidence as the phenotypic endpoint matching the human syndrome.
      evidence:
      - reference: PMID:35727838
        reference_title: "A mouse model for Li-Fraumeni-Like Syndrome with cardiac angiosarcomas associated to POT1 mutations."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "As in human Li-Fraumeni patients, heterozygous Pot1a+/ki mice spontaneously develop a high incidence of angiosarcomas, including cardiac angiosarcomas, and this is associated to the presence of abnormally long telomeres in endothelial cells as well as in the tumors."
        explanation: >-
          Reports both the tumor incidence and the endothelial localization of the long
          telomeres, joining the mechanism to the lineage.
    evidence:
    - reference: PMID:35727838
      reference_title: "A mouse model for Li-Fraumeni-Like Syndrome with cardiac angiosarcomas associated to POT1 mutations."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "The Pot1a+/R117C mouse model constitutes a useful tool to understand human cancers initiated by POT1 mutations."
      explanation: The authors' own statement of the model's scope for this syndrome.
genetic:
- name: POT1
  gene_term:
    preferred_term: POT1
    term:
      id: hgnc:17284
      label: POT1
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  association: >-
    Heterozygous germline loss of function variants in POT1 cause POT1 tumor
    predisposition syndrome.
  notes: >-
    Reported alleles include missense (p.Arg117Cys, p.Tyr36Cys, p.Gln376Arg),
    nonsense, frameshift (p.Gln358SerfsTer13) and splice site (c.1164-1G>A) changes,
    distributed across the reading frame. They fall into two mechanistic classes:
    those that disrupt POT1 binding to the single stranded telomeric overhang, and
    those that disrupt the POT1 to ACD/TPP1 interface within shelterin. Germline
    variants in other shelterin components, ACD and TERF2IP, have been found in
    comparable families, so a POT1-negative pedigree of this shape is not
    necessarily shelterin-negative.
  evidence:
  - reference: PMID:27528712
    reference_title: "Germ line mutations in shelterin complex genes are associated with familial chronic lymphocytic leukemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The c.1164-1G>A splice-site, p.Gln358SerfsTer13 frameshift, and p.Gln376Arg missense mutations are likely to impact the interaction between POT1 and adrenocortical dysplasia homolog (ACD), which is a part of the telomere-capping shelterin complex."
    explanation: Defines the second mechanistic class of alleles, those acting through the ACD interface.
  - reference: PMID:27528712
    reference_title: "Germ line mutations in shelterin complex genes are associated with familial chronic lymphocytic leukemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We also identified mutations in ACD (c.752-2A>C) and another shelterin component, telomeric repeat binding factor 2, interacting protein (p.Ala104Pro and p.Arg133Gln), in 3 CLL families."
    explanation: >-
      Supports the note that other shelterin genes produce comparable familial disease,
      which matters when POT1 sequencing is negative.
  - reference: PMID:26403419
    reference_title: "A mutation in the POT1 gene is responsible for cardiac angiosarcoma in TP53-negative Li-Fraumeni-like families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The mutation is recently found once in 121,324 studied alleles in ExAC server but it is not described in any other database or found in 1,520 Spanish controls."
    explanation: Establishes the rarity of the discovery allele in population and control datasets.
treatments:
- name: Melanoma Surveillance
  description: >-
    Full skin examination by a dermatologist from age 18 years at least six monthly,
    with excision of suspicious lesions, intensified to three monthly for those with
    multiple atypical nevi or a melanoma history. Monthly self examination is
    encouraged alongside it.
  treatment_term:
    preferred_term: Cancer Screening
    term:
      id: NCIT:C15406
      label: Cancer Screening
  target_mechanisms:
  - target: Cutaneous Melanoma
  evidence:
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Full skin examination by a dermatologist beginning at age 18 years at least every six months with excision of any lesions suspicious for melanoma"
    explanation: The GeneReviews dermatologic surveillance recommendation.
- name: Whole-Body MRI and Hematologic Surveillance
  description: >-
    Annual whole body MRI from age 18 years for non-cutaneous, non-brain
    malignancies, annual complete blood count with differential to screen for chronic
    lymphocytic leukemia, and brain MRI every one to two years depending on the
    family history of glioma.
  treatment_term:
    preferred_term: Cancer Screening
    term:
      id: NCIT:C15406
      label: Cancer Screening
  target_mechanisms:
  - target: Chronic Lymphatic Leukemia
  - target: Angiosarcoma
  - target: Glioma
  evidence:
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Annual whole-body MRI beginning at age 18 years, or earlier depending on personal and family history of non-cutaneous, non-brain malignancies."
    explanation: The GeneReviews whole-body imaging recommendation and its age trigger.
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Annual complete blood count with differential beginning at age 18 years to screen for CLL."
    explanation: The GeneReviews hematologic surveillance recommendation.
- name: Avoidance of Ultraviolet and Ionizing Radiation Exposure
  description: >-
    Tanning beds and unprotected sun exposure are to be avoided, as is radiation in
    diagnostic procedures. The radiation caution is why the imaging surveillance
    above is built on MRI rather than CT.
  treatment_term:
    preferred_term: Supportive Care
    term:
      id: NCIT:C15747
      label: Supportive Care
  target_mechanisms:
  - target: Cutaneous Melanoma
  evidence:
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Agents/circumstances to avoid: Tanning bed use and unprotected sun exposure; radiation in diagnostic procedures."
    explanation: The GeneReviews agents and circumstances to avoid statement.
  - reference: PMID:38254993
    reference_title: "Germline POT1 Variants: A Critical Perspective on POT1 Tumor Predisposition Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Furthermore, a proposal of a surveillance protocol related to the cancers associated with POT1 pathogenic variants requires reliable data to avoid an excessive, possibly unjustified, burden for POT1 variant carriers."
    explanation: >-
      Records the argument against applying maximal Li-Fraumeni-style surveillance to
      every carrier by default, which is a live caveat on the protocol above rather than
      a reason to omit it.
- name: Cascade Genetic Testing of First-Degree Relatives
  description: >-
    Targeted testing for the familial POT1 variant in first-degree relatives. This is
    the step that moves a relative from unknown risk into the surveillance protocol,
    which is why it is modeled as an intervention rather than left in counselling
    prose. GeneReviews does not generally recommend it below age 18, since the
    associated cancers are predominantly adult onset, unless the family history
    includes early cancers.
  treatment_term:
    preferred_term: Genetic Testing
    term:
      id: NCIT:C15709
      label: Genetic Testing
  evidence:
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Molecular genetic testing for the familial POT1 pathogenic variant should be offered to first-degree relatives to identify those who would benefit from early surveillance and intervention."
    explanation: The GeneReviews recommendation for testing at-risk relatives.
  - reference: PMID:33119245
    reference_title: "POT1 Tumor Predisposition."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Although molecular genetic testing for POT1-TPD is generally not recommended for at-risk individuals younger than age 18 years, a history of early cancers in the family may warrant predictive testing prior to age 18 years."
    explanation: >-
      Records the age threshold and its exception, which is the part that matters in a
      pediatric setting.
differential_diagnoses:
- name: Li-Fraumeni syndrome
  disease_term:
    preferred_term: Li-Fraumeni syndrome
    term:
      id: MONDO:0018875
      label: Li-Fraumeni syndrome
  description: >-
    The clinical starting point for most POT1-TPD diagnoses. POT1-TPD was identified
    by sequencing TP53-negative Li-Fraumeni-like families, and it remains the
    syndrome to consider when such a pedigree, particularly one containing
    angiosarcoma, has no TP53 variant.
  distinguishing_features:
  - A TP53 pathogenic variant establishes Li-Fraumeni syndrome; POT1 tumor predisposition is found in TP53-negative Li-Fraumeni-like pedigrees.
  - Cardiac angiosarcoma with multiple cutaneous melanomas favors POT1 tumor predisposition.
  - Childhood adrenocortical carcinoma, choroid plexus carcinoma, and early osteosarcoma favor Li-Fraumeni syndrome; POT1-associated cancers are predominantly adult onset.
  evidence:
  - reference: PMID:26403419
    reference_title: "A mutation in the POT1 gene is responsible for cardiac angiosarcoma in TP53-negative Li-Fraumeni-like families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We extend the analysis to TP53-negative LFL families with no CAS and find the same mutation in a breast AS family."
    explanation: >-
      Documents the TP53-negative Li-Fraumeni-like ascertainment route through which this
      syndrome is found.
- name: BAP1 tumor predisposition syndrome
  disease_term:
    preferred_term: BAP1-related tumor predisposition syndrome
    term:
      id: MONDO:0013692
      label: BAP1-related tumor predisposition syndrome
  description: >-
    The other tumor predisposition syndrome that presents through melanocytic lesions
    and is weighed alongside POT1 in a melanoma genetics clinic. BAP1 carriers develop
    uveal melanoma, mesothelioma, renal cell carcinoma and characteristic melanocytic
    tumors, a spectrum that overlaps POT1 only at cutaneous melanoma.
  distinguishing_features:
  - Uveal melanoma, mesothelioma or renal cell carcinoma favors BAP1-related tumor predisposition.
  - Cardiac angiosarcoma, glioma or chronic lymphocytic leukemia favors POT1 tumor predisposition.
  evidence:
  - reference: PMID:38254993
    reference_title: "Germline POT1 Variants: A Critical Perspective on POT1 Tumor Predisposition Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The Protection of Telomere 1 (POT1) gene was identified as a melanoma predisposition candidate nearly 10 years ago."
    explanation: >-
      Establishes melanoma predisposition as the entry point through which POT1 is
      considered, which is the setting in which this differential arises.
- name: Familial melanoma
  disease_term:
    preferred_term: familial melanoma
    term:
      id: MONDO:0018961
      label: familial melanoma
  description: >-
    CDKN2A and CDK4 account for most of the familial melanoma that has an identified
    cause, and POT1 was found by sequencing families that were negative for them. A
    POT1 diagnosis is therefore usually reached after these are excluded.
  distinguishing_features:
  - A CDKN2A or CDK4 pathogenic variant establishes the more common cause of familial melanoma.
  - Melanoma alongside cardiac angiosarcoma, glioma or chronic lymphocytic leukemia favors POT1 tumor predisposition.
  evidence:
  - reference: PMID:38254993
    reference_title: "Germline POT1 Variants: A Critical Perspective on POT1 Tumor Predisposition Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "While the key role, and related risks, of the alterations in POT1 in melanoma are established, the correlation between germline POT1 variants and the susceptibility to other cancers partially lacks evidence, due also to the rarity of POT1-TPD."
    explanation: >-
      Confirms melanoma as the established POT1 association, which is what places this
      syndrome in the familial melanoma differential in the first place.
- name: Dyskeratosis congenita
  disease_term:
    preferred_term: dyskeratosis congenita
    term:
      id: MONDO:0015780
      label: dyskeratosis congenita
  description: >-
    The mechanistic mirror image. Dyskeratosis congenita is a short telomere
    syndrome presenting with bone marrow failure, mucocutaneous findings, and
    pulmonary fibrosis; POT1 tumor predisposition is a long telomere syndrome
    presenting with solid tumors and leukemia, without the marrow failure phenotype.
  distinguishing_features:
  - Short telomeres with bone marrow failure and pulmonary fibrosis favor dyskeratosis congenita.
  - Abnormally long telomeres with melanoma, angiosarcoma, glioma, or chronic lymphocytic leukemia favor POT1 tumor predisposition.
  evidence:
  - reference: PMID:38839987
    reference_title: "POT1 tumour predisposition: a broader spectrum of associated malignancies and proposal for additional screening program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Protection of Telomeres Protein 1 (POT1) protein is an essential subunit of the shelterin telomere binding complex, regulating telomere length."
    explanation: >-
      Places POT1 in the shelterin complex shared with the telomere biology disorders,
      which is what makes this a mechanistic differential rather than a clinical one.
discussions:
- discussion_id: pot1_elongation_versus_instability
  kind: KNOWLEDGE_GAP
  status: OPEN
  prompt: >-
    Is tumorigenesis in POT1 tumor predisposition driven by telomere elongation
    extending replicative capacity, or by the genomic instability that follows an
    uncapped telomere?
  attaches_to:
  - pathophysiology#Telomere Fragility and Genomic Instability
  - pathophysiology#Unrestrained Telomerase Access and Telomere Elongation
  rationale: >-
    Both phenotypes are observed in POT1 variant carriers, and the literature has not
    resolved which one is causal. Human carrier studies report abnormally long
    telomeres together with increased telomere fragility, while CRISPR engineered
    human embryonic and hematopoietic stem cells carrying the same class of variant
    show consistent elongation with no detectable telomere damage response. The
    engineered stem cell result favours elongation as the selected property and is why
    the instability node on this entry is marked provisional, but it is a stem cell
    model rather than a tumor, so it does not close the question. The distinction
    matters practically: an instability driven mechanism would predict sensitivity to
    DNA damaging therapy that an elongation driven mechanism would not.
  evidence:
  - reference: PMID:33934394
    reference_title: "Cancer-associated POT1 mutations lead to telomere elongation without induction of a DNA damage response."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Cancers with caPOT1 mutations have elongated telomeres and show increased genomic instability, but which of the two phenotypes promotes tumorigenesis is unclear."
    explanation: >-
      The authors state the open question directly, which is what this discussion
      records rather than resolving.
references:
- reference: PMID:33119245
  title: POT1 Tumor Predisposition
  tags:
  - GeneReviews
- reference: PMID:32987645
  title: Role of POT1 in Human Cancer.

📚

References & Deep Research

References

2

PMID:33119245

POT1 Tumor Predisposition

No top-level findings curated for this source.

PMID:32987645

Role of POT1 in Human Cancer.

No top-level findings curated for this source.

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (2)

Take review suggestions on PR #10450 (POT1-TPD) · 2026-09-01T23:50:38Z · View source

Second response round on PR #10450, after the reviewer approved the blocking fixes and left six non-blocking notes. Four taken. The substantive one was fidelity on both Pot1a R117C mouse links, changed from HIGH to MODERATE. The entry contradicted itself: its own limitations lines said the Pot1a/Pot1b paralogue split bounds extrapolation to human POT1, and that the model covers only the angiosarcoma arm of a four-tumour spectrum, while the fidelity grade said the model captures the human mechanism faithfully. MODERATE is what those caveats already imply. This was the same misreading of the slot made on the SGBS1 entry in this series, where HIGH sat on a FAILS_TO_RECAPITULATE link; in both cases the value being encoded was how well characterised the result is rather than how faithfully the model maps to human biology, which is not what the slot means. Also taken: diagnosis_term bound to NCIT:C15709 (Genetic Testing), matching 416 other disorder entries; the telomerase-dependence readout now states that it is measured in Pot1a+/ki Tert-/- double mutants rather than the declared Pot1a+/ki genotype, since the comparison is the experiment and a reader should not have to infer it; and the GeneReviews genetic counseling gap closed with the 50% per-child transmission figure on inheritance and cascade testing of first-degree relatives as a treatment, carrying the age-18 threshold and its early-cancer exception. Not done, and the reason is the same for both. Genetic.case_fractions and the Ashkenazi p.Ile78Thr founder allele both need PMID:32987645 as full text; it is cached abstract_only, and the per-cohort figures the reviewer quoted (4/105, 7/56, 2/55) appear in the deep-research report rather than in anything a snippet can be verified against. Copying them from the report into a citation is the fabrication risk the evidence SOP exists to prevent. Re-fetching that paper as full text makes both straightforward. PMID:38573059 stays uncited for the same reason: its POT1 content could not be isolated to a quotable sentence. Validation: 41/41 snippets verified; validate, reference-titles, entity-refs, causal-targets, duplicate-keys, enum-values and snippet-grading all clean.

Create: POT1 Tumor Predisposition Syndrome · 2026-09-01T19:05:53Z · View source

De novo curation of POT1 tumor predisposition (MONDO:0014368, POT1) from a falcon/Edison deep-research report (research/POT1_Tumor_Predisposition_Syndrome-deep-research-falcon.md), with the GeneReviews POT1 Tumor Predisposition chapter (PMID:33119245) as the phenotype baseline. This was the cleanest of the three reports: its own validation recorded 9/9 references resolved and 17/17 terms resolved, with 7 of 9 references assessed on topic. It cited by DOI rather than PMID, so every DOI was converted through the PMC ID converter and the PMID cited in preference, per the reference-validator skip-prefix rule. Entry-type decision: MONDO places this term under two susceptibility parents (susceptibility to familial cutaneous melanoma, glioma susceptibility) and several synonyms are locus-style labels, which is the shape the claim-disease guidance treats as usually out of scope. It is curated as a DISEASE because it is a single-gene syndrome with one conserved mechanism upstream of a defined tumor spectrum and published surveillance guidance, matching the germline predisposition syndromes design decisions section 3a keeps as their own entries. The file is named POT1_Tumor_Predisposition_Syndrome rather than the MONDO label, which remains the disease_term binding. Mechanism is curated with its open question intact rather than resolved. Calvete 2015 (PMID:26403419) measured reduced telomere-bound POT1, long telomeres and increased fragility in human carriers; Kim 2021 (PMID:33934394) found no telomere damage response in CRISPR-engineered hESCs and HSCs and argues elongation is the selected property. The instability node carries mechanism_confidence PROVISIONAL and a REFUTE item from Kim, and an OPEN KNOWLEDGE_GAP discussion records the elongation-versus-instability question with the authors' own statement that it is unclear. Named Entity Confusion preflight PASS (POT1 mentioned 69 times; report OMIM 615848 matches MONDO). Validation: just validate passed; 28/28 snippets verified; validate-terms passed; check-entity-refs and check-causal-targets clean; whole-KB gates clean. Stub stubs/Tumor_Predisposition_Syndrome_3.yaml deleted.

Falcon ▸

POT1 Tumor Predisposition Syndrome: Disease Characteristics Research Report

Edison Scientific Literature 25 citations 2026-09-01T17:04:35.000711

POT1 Tumor Predisposition Syndrome: Disease Characteristics Research Report

Scope. This report prioritizes evidence available through 2024. POT1 tumor predisposition syndrome (POT1-TPD) remains exceptionally rare; penetrance estimates and many proposed tumor associations are not yet reliable. Accordingly, the report separates the well-supported core phenotype from hypothesis-generating case reports and small cohorts.

The principal evidence is summarized below.

Domain	Current evidence	Quantitative detail	Evidence strength
Identifiers	POT1 tumor predisposition syndrome corresponds to MONDO_0014368 (“tumor predisposition syndrome 3”); OMIM 615848 is cited in recent case literature and GeneReviews-derived sources.	MONDO_0014368; OMIM 615848	Moderate for MONDO disease mapping; moderate for OMIM based on disease resources and recent reports (OpenTargets Search: POT1 tumor predisposition syndrome-POT1, ardinger1993pot1tumorpredisposition pages 1-3)
Inheritance / penetrance	Inherited in an autosomal dominant manner; penetrance remains unknown and phenotype is incompletely defined.	50% transmission risk to offspring; de novo proportion unknown	Moderate-strong from GeneReviews-derived summaries and 2024 cohort framing (ardinger1993pot1tumorpredisposition pages 1-3, freitas2024pot1tumourpredisposition pages 1-2)
Core tumor spectrum	Best-supported associated malignancies are cutaneous melanoma, chronic lymphocytic leukemia, angiosarcoma (especially cardiac), and glioma. Other tumors have been proposed but remain less certain.	Melanoma onset reported from 15-80 years; most cancers diagnosed in adulthood	Strong for core spectrum; weaker for expanded spectrum (ardinger1993pot1tumorpredisposition pages 1-3, freitas2024pot1tumourpredisposition pages 1-2, andreotti2024germlinepot1variants pages 8-9)
2024 family cohort	A recent three-family report suggests a broader phenotype but should be interpreted cautiously.	37 tested relatives/individuals; 22 carriers; 51.4% female; median age 46 years (22-81)	Moderate, hypothesis-generating cohort evidence (freitas2024pot1tumourpredisposition pages 1-2)
Familial CLL evidence	Familial CLL association is supported by rare germline POT1 variants segregating in affected families; one variant also showed case-control enrichment.	4/66 CLL families with co-segregating POT1 LoF/likely deleterious variants; p.Gln376Arg OR 3.61, P=0.009 in 1,083 cases vs 5,854 controls	Strong for CLL association (speedy2016germlinemutations pages 1-5)
Molecular diagnosis	Diagnosis is established by identifying a heterozygous germline pathogenic/likely pathogenic POT1 variant in an appropriate clinical context. Sequence analysis plus del/dup analysis are recommended approaches.	Heterozygous germline pathogenic POT1 variant required	Strong for current diagnostic approach (ardinger1993pot1tumorpredisposition pages 1-3, ardinger1993pot1tumorpredispositiona pages 1-3)
Mechanism	POT1 dysfunction impairs shelterin-mediated telomere regulation. Human stem-cell and other models support telomere elongation and increased proliferative capacity as central effects; DNA damage signaling appears variant- and context-dependent rather than uniform.	Engineered hESC/HSC models showed telomere elongation without overt telomere damage for tested variants; mouse/tumor models show RPA-ATR DDR involvement in some contexts	Strong mechanistic support, but variant-specific heterogeneity remains (kim2021cancer‐associatedpot1mutations pages 1-2, takasugi2023pot1b−−tumors pages 1-2, calvete2015amutationin pages 1-2, martinez2022amousemodel pages 1-2)
Surveillance	Expert-opinion surveillance includes dermatologic skin examination, annual CBC with differential, annual physical examination, and MRI-based screening individualized by personal/family history.	Skin exam every 6 months from age 18, or every 3-6 months in higher-risk melanoma settings; annual CBC/physical exam; whole-body MRI annually in selected families; brain MRI every 1-2 years when indicated	Moderate, largely expert-opinion due to limited penetrance data (ardinger1993pot1tumorpredisposition pages 1-3, ardinger1993pot1tumorpredisposition pages 5-8, hansford2024updateoncancer pages 1-2)
Therapy / management	No syndrome-specific targeted therapy is established; management is standard-of-care treatment for each tumor plus risk-reduction and cascade testing.	No POT1-TPD-specific interventional trials identified; exposure avoidance includes tanning beds/unprotected sun and unnecessary diagnostic radiation	Moderate for absence of syndrome-specific therapy; strong for current standard management framing (freitas2024pot1tumourpredisposition pages 1-2, ardinger1993pot1tumorpredisposition pages 5-8)
Models	Disease biology has been modeled in human embryonic stem cells, hematopoietic stem cells, mouse embryonic fibroblasts, Pot1a R117C knock-in mice, and serially passaged Pot1b-null sarcoma models.	Pot1a+/ki mice developed a high incidence of angiosarcomas including cardiac angiosarcoma; serial Pot1b-null tumors developed hyper-elongated telomeres	Strong for availability and utility of model systems, with known mouse-human Pot1 biology differences (kim2021cancer‐associatedpot1mutations pages 1-2, takasugi2023pot1b−−tumors pages 1-2, martinez2022amousemodel pages 1-2)

Table: This table summarizes the most actionable current evidence for POT1 tumor predisposition syndrome, highlighting what is well-supported versus still uncertain. It is useful as a compact reference for identifiers, diagnosis, mechanism, surveillance, and the strongest human and model-system data.

1. Disease information

Definition

POT1-TPD is a Mendelian, autosomal-dominant hereditary cancer-predisposition syndrome caused by a heterozygous germline pathogenic or likely pathogenic variant in POT1, which encodes a single-stranded telomeric-DNA-binding component of shelterin. The best-supported tumors are multiple cutaneous melanomas, chronic lymphocytic leukemia (CLL), angiosarcoma—particularly cardiac angiosarcoma—and glioma. Most cancers occur in adulthood, although melanoma has been reported from age 15 onward. Penetrance and the complete tumor spectrum remain unknown. (ardinger1993pot1tumorpredisposition pages 1-3, freitas2024pot1tumourpredisposition pages 1-2)

Identifiers and synonyms

MONDO: MONDO:0014368, tumor predisposition syndrome 3.
OMIM phenotype: 615848, commonly called tumor predisposition syndrome 3.
Gene: POT1, protection of telomeres 1; Ensembl ENSG00000128513; chromosome 7q31.33. Open Targets gives POT1–MONDO:0014368 an association score of approximately 0.816, supported by multiple genetic studies. (OpenTargets Search: POT1 tumor predisposition syndrome-POT1, freitas2024pot1tumourpredisposition pages 1-2)
Common names: POT1 tumor predisposition; POT1 tumor predisposition syndrome; POT1-TPD; POT1-associated hereditary cancer syndrome; tumor predisposition syndrome 3.
Orphanet: No confidently verified syndrome-specific ORPHA number was recovered.
ICD-10/ICD-11 and MeSH: No unique POT1-TPD code/descriptor was identified. Coding generally uses a hereditary cancer-susceptibility code plus codes for the particular neoplasm and genetic finding.

The evidence is aggregated at the disease/family level from GeneReviews, pedigrees, cancer cohorts, ClinVar-like variant resources, and experimental studies—not derived from a single EHR population. Individual case reports contribute mainly to proposed expansion of the phenotype.

2. Etiology

Causal factor

The necessary inherited lesion is a heterozygous germline pathogenic/likely pathogenic POT1 variant. Reported disease-associated classes include missense, nonsense, frameshift, and splice-site variants. Variants may impair binding of POT1 to telomeric DNA through its N-terminal OB folds or disrupt its C-terminal interaction with ACD/TPP1, thereby altering shelterin function. Loss of heterozygosity is not consistently required; several engineered and clinical observations support a dominant-negative or haploinsufficient effect, depending on the allele. (kim2021cancer‐associatedpot1mutations pages 1-2, speedy2016germlinemutations pages 1-5, calvete2015amutationin pages 1-2)

Genetic risk factors

Foundational human studies include:

Familial melanoma cohorts identified POT1 variants in 4/105 (3.8%) CDKN2A/CDK4-negative families and 7/56 (12.5%) Italian families. Reported alleles included p.Tyr89Cys, p.Gln94Glu, p.Arg273Leu, c.1687-1G>A, p.Ser270Asn, p.Arg137His, and p.Gln623His. The landmark 2014 melanoma papers are indexed under PMIDs 24686846 and 24686849. (OpenTargets Search: POT1 tumor predisposition syndrome-POT1, wu2020roleofpot1 pages 5-8)
In familial glioma, POT1 p.Gly95Cys and p.Glu450Ter were detected in 2/55 families (3.6%); the implicated families notably included oligodendroglioma. (webster2023germlinepot1gene pages 16-19, wu2020roleofpot1 pages 5-8)
Whole-exome sequencing of 66 CLL families identified four families with co-segregating POT1 variants: p.Tyr36Cys, p.Gln376Arg, p.Gln358SerfsTer13, and c.1164-1G>A. In 1,083 cases and 5,854 controls, p.Gln376Arg—global minor-allele frequency 0.0005—conferred an estimated 3.61-fold CLL risk (P=0.009). Published online August 15, 2016; DOI: 10.1182/blood-2016-01-695692. The abstract states: “loss-of-function mutations in POT1 co-segregated with CLL.” (speedy2016germlinemutations pages 1-5)
POT1 p.Arg117Cys was found in several TP53-negative Li–Fraumeni-like families containing cardiac angiosarcoma. It was absent from 1,520 Spanish controls and observed once among 121,324 ExAC alleles. Published September 25, 2015; DOI: 10.1038/ncomms9383. (calvete2015amutationin pages 1-2)

Modifier genes: No validated modifier gene is established. Somatic BRAF, NRAS, or KIT alterations can cooperate in melanocytic lesions, and KDR/VEGF-pathway alterations have been reported in cardiac angiosarcoma, but these are tumor drivers rather than proven germline modifiers.

Environmental and protective factors

No exposure causes the inherited syndrome. UV radiation is an established melanoma risk factor generally, but its specific contribution to POT1-associated melanoma is unresolved; one review notes no demonstrated POT1-specific UV effect, while molecular analysis of p.Ile78Thr-associated lesions found a UV mutational signature. Sun avoidance therefore remains prudent despite uncertain gene-specific interaction. (ardinger1993pot1tumorpredispositiona pages 5-8, ardinger1993pot1tumorpredisposition pages 5-8)

No genetic protective allele, diet, medication, or lifestyle intervention has been shown to neutralize POT1-TPD risk. Avoidance of tanning beds, unprotected ultraviolet exposure, tobacco, and unnecessary ionizing radiation is reasonable risk reduction, not proven syndrome-specific prevention.

3. Phenotypes

POT1-TPD generally has no congenital dysmorphism or obligate non-neoplastic phenotype. The manifestations are tumors and their site-specific symptoms.

Cutaneous melanoma: Multiple primary melanomas may occur; reported onset 15–80 years, generally adult, with variable severity and recurrence. Suggested HPO: HP:0002861 Melanoma, HP:0008069 Neoplasm of the skin, and multiple primary neoplasm where locally supported. Functional and quality-of-life effects depend on stage, surgery, disfigurement, metastatic disease, and surveillance burden. (ardinger1993pot1tumorpredisposition pages 1-3)
CLL: Usually adult/late-onset; may be asymptomatic lymphocytosis or progressive nodal, marrow, and systemic disease. Suggested HPO: HP:0001909 Leukemia, HP:0002716 Lymphadenopathy, HP:0004313 Decreased circulating antibody level, HP:0001873 Thrombocytopenia, and HP:0001923 Reticulocytopenia/anemia terms as documented clinically. POT1 variants have been reported in approximately 3.5% of CLL in one summarized dataset, but that figure includes tumor-level observations and is not the prevalence of germline POT1-TPD. (feldman1993pot1tumorpredisposition pages 5-7)
Angiosarcoma: Particularly cardiac, but breast and other soft-tissue sites have been reported. Severity is often high and progression can be rapid. Suggested HPO: HP:0030448 Angiosarcoma where available, HP:0003002 Breast carcinoma, and site-specific cardiac neoplasm terms. Cardiac disease can cause dyspnea, arrhythmia, obstruction, effusion, heart failure, or embolic/metastatic complications.
Glioma: Histologies include oligodendroglial and other diffuse gliomas; symptoms depend on site and include headache, seizure, focal weakness, behavior/personality change, vomiting, or impaired balance. Suggested HPO: HP:0009733 Glioma, HP:0001250 Seizure, HP:0002315 Headache, and HP:0004372 Reduced consciousness when present. Pediatric CNS-tumor guidance emphasizes that approximately 15–21% of childhood CNS tumors overall are associated with predisposition syndromes, but this is not a POT1-specific frequency. (webster2023germlinepot1gene pages 16-19, hansford2024updateoncancer pages 1-2)

The proposed expanded spectrum includes other sarcomas, papillary thyroid carcinoma, hematologic malignancies, colorectal cancer, prostate cancer, breast cancer, lung cancer, renal cancer, and GIST. These should be annotated as limited or emerging evidence, not as established penetrant features. A 2024 series of three multigenerational families tested 37 people—19 women and 18 men, median age 46 years—and found the familial POT1 variant in 22; additional sarcomas, papillary thyroid cancer, early-onset prostate cancer, and leukemia were observed. DOI: 10.1038/s41431-024-01611-0, published online June 5, 2024. (freitas2024pot1tumourpredisposition pages 1-2)

No POT1-specific EQ-5D, SF-36, PROMIS, disability, or behavioral-phenotype studies were identified.

4. Genetic and molecular information

Gene and protein

POT1, chromosome 7q31.33; approved name protection of telomeres 1.
Protein function: binds the 3′ single-stranded TTAGGG telomeric overhang; interacts with ACD/TPP1; limits inappropriate RPA–ATR damage signaling and regulates telomerase access and telomere length. (freitas2024pot1tumourpredisposition pages 1-2, kim2021cancer‐associatedpot1mutations pages 1-2)
Suggested GO cellular components: telomere, nuclear chromosome telomeric region, shelterin complex, nucleus.
Suggested GO functions/processes: single-stranded telomeric DNA binding, telomere capping, telomere maintenance, negative regulation of telomerase activity, negative regulation of DNA-damage response, and chromosome-end protection.

Representative germline variants

p.Arg117Cys: missense, OB-fold region; reduced telomere-bound POT1, long and fragile telomeres; dominant-negative behavior in the Pot1a knock-in model; associated particularly with cardiac angiosarcoma families. (calvete2015amutationin pages 1-2, martinez2022amousemodel pages 1-2)
p.Tyr36Cys: missense affecting telomeric-overhang interaction.
p.Gln376Arg, p.Gln358SerfsTer13, c.1164-1G>A: affect or are predicted to affect the POT1–ACD interaction; familial CLL evidence. (speedy2016germlinemutations pages 1-5)
p.Gly95Cys, p.Glu450Ter, p.Asp617GlufsTer9: reported in glioma families. (andreotti2024germlinepot1variants pages 5-6)
p.Ile78Thr/c.233T>C, p.Gln623His, p.Ser270Asn, p.Arg137His: recurrent familial melanoma-associated alleles.
The 2024 family study examined c.349C>T, c.233T>C, and c.818G>A. (freitas2024pot1tumourpredisposition pages 1-2)

Pathogenicity must be assessed per ACMG/AMP criteria using population rarity, segregation, phenotype specificity, RNA evidence for splice variants, functional assays, and curated clinical evidence. A VUS does not establish POT1-TPD and should not drive predictive testing or irreversible management. Many reported POT1 substitutions remain VUS because segregation and standardized functional evidence are lacking. (ardinger1993pot1tumorpredisposition pages 1-3, andreotti2024germlinepot1variants pages 8-9)

Disease-causing alleles are expected to be very rare in gnomAD; no single carrier-frequency estimate is validated. Somatic POT1 variants also occur in tumors and can suggest germline testing, but tumor-only detection does not prove constitutional origin. Constitutional confirmation should use blood or saliva, and cultured fibroblasts when hematologic malignancy or clonal hematopoiesis could confound blood testing.

No recurrent syndrome-defining chromosomal rearrangement, methylation signature, or epigenetic defect is established.

5. Environmental information

UV exposure: relevant to melanoma prevention, but POT1-specific effect size is unknown.
Ionizing radiation: not known to cause POT1-TPD; unnecessary diagnostic radiation is often avoided because lifelong surveillance is required and MRI/ultrasonography can reduce cumulative exposure. (ardinger1993pot1tumorpredisposition pages 5-8)
Smoking, alcohol, diet, exercise, occupational toxins, pollution: no POT1-specific quantitative evidence.
Infectious agents: none causes or triggers the syndrome. Infection can complicate CLL-related immune dysfunction but is downstream, not etiologic.

6. Mechanism and pathophysiology

Ordered causal chain

A heterozygous germline pathogenic POT1 variant leads to reduced or altered POT1 binding to telomeric single-stranded DNA and/or impaired interaction with ACD/TPP1.
Altered POT1–shelterin function leads to defective control of telomerase access, telomeric-overhang processing, and—in a variant/context-dependent manner—RPA exclusion and ATR signaling. (kim2021cancer‐associatedpot1mutations pages 1-2, speedy2016germlinemutations pages 1-5)
This commonly results in progressive telomere elongation; some alleles also result in telomere fragility and chromosome instability. (calvete2015amutationin pages 1-2)
Long telomeres lead to delayed replicative senescence and an extended proliferative lifespan, increasing the time during which a premalignant clone can acquire cooperating mutations. Human stem-cell work supports this step without requiring overt telomeric damage. (kim2021cancer‐associatedpot1mutations pages 1-2)
Mechanistic branch A: in telomerase-positive precursor cells, increased telomerase-mediated extension leads to sustained clonal expansion and malignant transformation.
Mechanistic branch B: where telomeric structures accumulate, unresolved G-quadruplexes lead to RPA binding and ATR-dependent DNA-damage signaling, which can recruit telomerase and further hyper-elongate telomeres; this branch is demonstrated in Pot1b-null mouse sarcomas and inferred, not proven universally, in human carriers. (takasugi2023pot1b−−tumors pages 1-2)
Tissue-specific cooperating drivers then lead to melanocytic, B-cell, glial, or endothelial malignancy; why these lineages are preferentially affected remains incompletely understood.
Tumor growth, invasion, hemorrhage, marrow replacement, or CNS mass effect then results in the clinical manifestations of melanoma, CLL, angiosarcoma, or glioma.

Experimental support

CRISPR/Cas9-engineered human embryonic and hematopoietic stem cells carrying cancer-associated POT1 variants showed telomere elongation but no overt telomere-damage response or competitive disadvantage. The authors concluded that these variants may be selected because they “elongate telomeres and extend the proliferative capacity” of incipient cancer cells. Published May 2, 2021; DOI: 10.15252/embj.2020107346. (kim2021cancer‐associatedpot1mutations pages 1-2)

In serially transplanted Pot1b-null mouse sarcomas, early tumors had short telomeres but late-generation tumors developed markedly hyper-elongated telomeres. Telomeric G-quadruplexes were recognized by RPA, activating ATR and telomerase recruitment. Published August 10, 2023; DOI: 10.1093/nar/gkad648. (takasugi2023pot1b−−tumors pages 1-2)

Suggested GO terms include telomere maintenance, telomerase-mediated telomere elongation, DNA-damage response, ATR signaling, chromosome organization, replicative senescence, cell-population proliferation, and regulation of apoptosis. Suggested cell types include melanocyte (CL:0000148), B lymphocyte (CL:0000236), endothelial cell (CL:0000115), glial lineage cells, hematopoietic stem cell, and embryonic stem cell. No reproducible POT1-TPD-specific metabolomic, lipidomic, proteomic, single-cell, spatial-transcriptomic, or methylation signature has been established.

7. Anatomical structures affected

Primary sites reflect the tumor spectrum:

Skin/melanocytic system: epidermis and dermal–epidermal melanocytic compartment; UBERON suggestions: skin of body, epidermis.
Hematolymphoid system: blood, bone marrow, lymph nodes, spleen; UBERON: blood, bone marrow, lymph node, spleen.
Cardiovascular/mesenchymal system: cardiac endothelium and other vascular/soft-tissue sites; UBERON: heart, blood vessel, connective tissue.
Central nervous system: brain and glial tissues; UBERON: brain, cerebral hemisphere, white matter as tumor location warrants.

At the subcellular level, the critical structures are the nucleus, chromosome ends/telomeres, single-stranded telomeric overhang, and shelterin complex. Lateralization is tumor-specific; the syndrome has no characteristic unilateral or bilateral pattern.

8. Temporal development

The genotype is constitutional from conception, but the phenotype is usually insidious and age-dependent. Most tumors occur in adulthood; the earliest reported first primary was at age 15. Surveillance is commonly started at age 18 or 2–5 years before the earliest familial diagnosis. (ardinger1993pot1tumorpredisposition pages 1-3, freitas2024pot1tumourpredisposition pages 1-2)

There is no syndrome-level staging system. Each tumor follows its standard AJCC/WHO staging and grading. The syndrome is lifelong; carriers can develop metachronous multiple primary tumors. Remission is treatment-induced and tumor-specific. No evidence supports spontaneous syndrome remission, anticipation, or a defined critical developmental window beyond age-based screening.

9. Inheritance and population

Inheritance: autosomal dominant; each child of a heterozygous carrier has a 50% chance of inheriting the variant. (ardinger1993pot1tumorpredisposition pages 1-3)
Penetrance: incomplete or at least age-dependent and currently unknown. Published families are highly ascertained and unsuitable for unbiased lifetime-risk estimates. (andreotti2024germlinepot1variants pages 8-9, freitas2024pot1tumourpredisposition pages 1-2)
Expressivity: markedly variable, including unaffected adult carriers and carriers with multiple primary cancers.
De novo variation: possible, but its proportion is unknown.
Mosaicism/germline mosaicism: no established frequency.
Anticipation: not demonstrated.
Consanguinity: not relevant to the dominant inheritance pattern.
Founder effects: p.Ile78Thr/c.233T>C has recurred in melanoma pedigrees of Jewish/Ashkenazi ancestry, suggesting a founder allele; founder-associated enrichment should not be generalized to all populations.
Prevalence/incidence: no defensible cases-per-100,000 estimate exists. Only several hundred probands had reportedly been tested by 2024. (freitas2024pot1tumourpredisposition pages 1-2)
Sex ratio: no established sex bias. The 2024 family cohort was 51.4% female, but this is not a population estimate. (freitas2024pot1tumourpredisposition pages 1-2)

10. Diagnostics

Clinical suspicion

Consider POT1-TPD in a person with:

Multiple primary cutaneous melanomas;
A core POT1 tumor plus a first- or second-degree relative with melanoma, CLL, angiosarcoma, or glioma;
Cardiac angiosarcoma or a TP53-negative Li–Fraumeni-like pedigree;
Familial oligodendroglioma/glioma; or
A potentially pathogenic POT1 alteration identified by tumor sequencing. (freitas2024pot1tumourpredisposition pages 1-2)

Molecular confirmation

Diagnosis requires a heterozygous germline pathogenic/likely pathogenic POT1 variant. Appropriate methods are:

hereditary melanoma, brain-tumor, hematologic-malignancy, sarcoma, or broad hereditary-cancer multigene panels containing POT1;
POT1 sequence analysis with deletion/duplication analysis;
targeted familial-variant testing for relatives;
WES/WGS when panel testing is negative but suspicion remains, particularly for unusual splice, structural, or noncoding lesions.

CMA, karyotyping, FISH, mitochondrial testing, and repeat-expansion testing are not routine diagnostic approaches. RNA studies may clarify splice variants. Telomere-length measurement can support functional investigation but is not sufficiently standardized or specific to diagnose POT1-TPD. (andreotti2024germlinepot1variants pages 8-9, speedy2016germlinemutations pages 1-5)

Surveillance tests

Expert-opinion practice includes:

full-body dermatologic examination at least every six months from age 18; every 3–6 months for multiple atypical nevi or personal/family melanoma history;
annual complete blood count with differential and clinical examination of lymph nodes;
annual comprehensive physical examination;
annual whole-body MRI in Li–Fraumeni/Li–Fraumeni-like families and individualized 1–2-year MRI in other selected carriers;
brain MRI every 1–2 years where family history supports glioma risk. (ardinger1993pot1tumorpredisposition pages 1-3, ardinger1993pot1tumorpredisposition pages 5-8, freitas2024pot1tumourpredisposition pages 1-2)

There are no universally validated biochemical biomarkers, liquid-biopsy tests, or syndrome-specific histopathologic criteria. Differential diagnoses include CDKN2A/CDK4 familial melanoma, BAP1 tumor-predisposition syndrome, Li–Fraumeni syndrome, hereditary retinoblastoma, constitutional mismatch-repair deficiency/Lynch-spectrum syndromes, DICER1 syndrome, NF1/NF2, and other shelterin/telomere-gene disorders. Unlike classic short-telomere syndromes, POT1-TPD is generally associated with long telomeres and lacks obligate marrow failure, pulmonary fibrosis, or mucocutaneous features.

11. Outcome and prognosis

No POT1-TPD-specific overall survival, life expectancy, 5-year survival, mortality rate, disability burden, or quality-of-life dataset exists. Prognosis is dominated by tumor type, anatomic site, stage, grade, treatment response, and the occurrence of multiple primaries.

Historical cardiac-angiosarcoma data cited in the p.Arg117Cys study describe a poor prognosis: sporadic angiosarcoma 5-year survival of approximately 14%, and mean survival of four months in the cited familial cases. These values are old, small-series estimates and should not be treated as a modern POT1-carrier survival estimate. (calvete2015amutationin pages 1-2)

Potential prognostic factors include early detection, metastatic status, cardiac involvement, glioma grade/molecular class, CLL cytogenetics and stage, melanoma Breslow depth, and somatic driver profile. Telomere length or POT1 genotype is not yet a validated clinical prognostic biomarker.

12. Treatment

There is no approved POT1-TPD-specific drug, gene therapy, RNA therapy, or preventive telomere-directed treatment. Tumors are treated according to standard histology- and stage-specific guidelines. (freitas2024pot1tumourpredisposition pages 1-2)

Melanoma: surgical excision; sentinel-node procedures when indicated; immune-checkpoint inhibitors and BRAF/MEK inhibition according to somatic genotype and stage. Suggested NCIt concepts: melanoma surgery, pembrolizumab, nivolumab, ipilimumab, dabrafenib, trametinib.
CLL: observation for asymptomatic early disease; BTK inhibitors, venetoclax-based regimens, anti-CD20 antibodies, or other guideline-based combinations when treatment criteria are met. Suggested NCIt: ibrutinib/acalabrutinib/zanubrutinib, venetoclax, obinutuzumab.
Glioma: maximal safe resection, radiotherapy, temozolomide, tumor-specific targeted therapy, and supportive neuro-oncology care as appropriate.
Angiosarcoma: resection when feasible, systemic chemotherapy and/or radiotherapy; cardiac disease requires multidisciplinary sarcoma, cardiothoracic, and transplant expertise.

Cell-line observations suggest that long telomeres/POT1 upregulation may influence radiotherapy resistance and motivate POT1 or telomerase inhibition research, but this is not clinically validated. Germline status presently guides surveillance and family counseling rather than selection of an approved POT1-targeted agent. (freitas2024pot1tumourpredisposition pages 1-2)

A ClinicalTrials.gov-oriented search found no POT1-TPD-specific interventional trial. Enrollment should therefore be based on the patient’s tumor histology and actionable somatic alterations rather than the syndrome alone.

13. Prevention

Primary prevention: the germline state cannot currently be prevented after conception. Counsel on sun protection, avoidance of tanning beds, smoking cessation, healthy weight, and minimizing unnecessary radiation; only photoprotection has an obvious tumor-specific rationale, and no POT1-specific risk reduction has been quantified.
Secondary prevention: cascade genetic testing and structured skin, hematologic, physical, and MRI surveillance are the principal real-world interventions. (ardinger1993pot1tumorpredisposition pages 1-3, ardinger1993pot1tumorpredisposition pages 5-8)
Tertiary prevention: tumor-specific follow-up to detect recurrence, second primaries, therapy complications, and CLL-associated infection or immune dysfunction.
Reproductive options: preimplantation genetic testing for monogenic disease and prenatal diagnosis are technically possible once a familial pathogenic variant is known; these require nondirective genetic counseling.
Testing minors: generally deferred until surveillance would change, but testing before 18 can be considered when a family contains childhood or adolescent cancers. (ardinger1993pot1tumorpredisposition pages 5-8)
Vaccination/prophylactic medication: no syndrome-specific vaccine or chemoprevention exists.

14. Other species and natural disease

No well-established naturally occurring veterinary syndrome directly equivalent to human POT1-TPD was identified, and no breed-specific VBO association or zoonotic relevance applies. POT1 and telomere-end protection are evolutionarily conserved across eukaryotes, but rodents possess Pot1a and Pot1b, partitioning functions performed by the single human POT1 protein. This limits direct extrapolation from knockout phenotypes. (takasugi2023pot1b−−tumors pages 1-2)

Suggested taxa: human NCBI Taxon 9606; laboratory mouse NCBI Taxon 10090. The condition is inherited, not transmissible or zoonotic.

15. Model organisms and experimental systems

Human cellular models

CRISPR/Cas9-engineered human embryonic stem cells and hematopoietic stem cells carrying heterozygous cancer-associated POT1 variants model the clinically relevant allelic state. They reproduce telomere elongation and extended proliferative potential but, for the tested alleles, not strong telomere-damage signaling. This demonstrates that elongation can be uncoupled from overt deprotection. (kim2021cancer‐associatedpot1mutations pages 1-2)

Pot1a p.Arg117Cys knock-in mouse

Heterozygous Pot1a+/R117C mice and mouse embryonic fibroblasts have longer telomeres than wild-type controls; elongation disappears in a Tert-null background, showing telomerase dependence. The allele exerts dominant-negative effects, and mice spontaneously develop a high incidence of angiosarcoma, including cardiac angiosarcoma, with long telomeres in endothelial cells and tumors. Published June 21, 2022; DOI: 10.1371/journal.pgen.1010260. The abstract states that the model “constitutes a useful tool to understand human cancers initiated by POT1 mutations.” (martinez2022amousemodel pages 1-2)

Pot1b-null sarcoma model

Serial transplantation of Pot1b-null sarcomas in immunodeficient mice models adaptive telomere hyper-elongation and revealed the G-quadruplex–RPA–ATR–telomerase mechanism. It is valuable for mechanistic and preclinical telomere studies but does not reproduce a heterozygous human germline syndrome or its complete tumor spectrum. (takasugi2023pot1b−−tumors pages 1-2)

No validated zebrafish, Drosophila, C. elegans, canine, feline, organoid, or patient-derived iPSC model was identified specifically for POT1-TPD.

Evidence appraisal and current expert interpretation

The most defensible knowledge-base representation is: POT1-TPD is a rare, autosomal-dominant, long-telomere cancer-predisposition syndrome with established associations to melanoma and meaningful evidence for CLL, angiosarcoma, and glioma, but unknown penetrance and incompletely defined variant-specific risks. The 2024 critical review cautioned that many non-core associations rely on single cases, incompletely classified variants, absent segregation, or nonstandardized telomere assays. It advised against automatically applying maximal Li–Fraumeni-style surveillance to every carrier, except where variant and family history—especially sarcoma history—justify it. (andreotti2024germlinepot1variants pages 8-9, andreotti2024germlinepot1variants pages 5-6)

Consequently, surveillance should be individualized in a multidisciplinary hereditary-cancer clinic, and broad tumor associations should be upgraded only after replicated segregation, robust functional validation, and unbiased carrier cohorts provide quantitative penetrance estimates.

References

(OpenTargets Search: POT1 tumor predisposition syndrome-POT1): Open Targets Query (POT1 tumor predisposition syndrome-POT1, 9 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.
(ardinger1993pot1tumorpredisposition pages 1-3): HH Ardinger and RA Pagon. Pot1 tumor predisposition. Unknown journal, 1993.
(freitas2024pot1tumourpredisposition pages 1-2): Marta Baptista Freitas, Laurence Desmyter, Cindy Badoer, Guillaume Smits, Isabelle Vandernoot, and Daphné t´Kint de Roodenbeke. Pot1 tumour predisposition: a broader spectrum of associated malignancies and proposal for additional screening program. European Journal of Human Genetics, 32:980-986, Jun 2024. URL: https://doi.org/10.1038/s41431-024-01611-0, doi:10.1038/s41431-024-01611-0. This article has 18 citations and is from a domain leading peer-reviewed journal.
(andreotti2024germlinepot1variants pages 8-9): Virginia Andreotti, Irene Vanni, Lorenza Pastorino, Paola Ghiorzo, and William Bruno. Germline pot1 variants: a critical perspective on pot1 tumor predisposition syndrome. Jan 2024. URL: https://doi.org/10.3390/genes15010104, doi:10.3390/genes15010104. This article has 9 citations.
(speedy2016germlinemutations pages 1-5): Helen E. Speedy, Ben Kinnersley, Daniel Chubb, Peter Broderick, Philip J. Law, Kevin Litchfield, Sandrine Jayne, Martin J. S. Dyer, Claire Dearden, George A. Follows, Daniel Catovsky, and Richard S. Houlston. Germ line mutations in shelterin complex genes are associated with familial chronic lymphocytic leukemia. Blood, 128 19:2319-2326, Nov 2016. URL: https://doi.org/10.1182/blood-2016-01-695692, doi:10.1182/blood-2016-01-695692. This article has 170 citations and is from a highest quality peer-reviewed journal.
(ardinger1993pot1tumorpredispositiona pages 1-3): HH Ardinger and RA Pagon. Pot1 tumor predisposition. Unknown journal, 1993.
(kim2021cancer‐associatedpot1mutations pages 1-2): Won‐Tae Kim, Kelsey Hennick, Joshua Johnson, Brendan Finnerty, Seunga Choo, Sarah B Short, Casey Drubin, Ryan Forster, Mary L McMaster, and Dirk Hockemeyer. Cancer‐associated pot1 mutations lead to telomere elongation without induction of a dna damage response. The EMBO Journal, May 2021. URL: https://doi.org/10.15252/embj.2020107346, doi:10.15252/embj.2020107346. This article has 64 citations.
(takasugi2023pot1b−−tumors pages 1-2): Taylor Takasugi, Peili Gu, Fengshan Liang, Isabelle Staco, and Sandy Chang. Pot1b −/− tumors activate g-quadruplex-induced dna damage to promote telomere hyper-elongation. Nucleic Acids Research, 51:9227-9247, Aug 2023. URL: https://doi.org/10.1093/nar/gkad648, doi:10.1093/nar/gkad648. This article has 15 citations and is from a highest quality peer-reviewed journal.
(calvete2015amutationin pages 1-2): Oriol Calvete, Paula Martinez, Pablo Garcia-Pavia, Carlos Benitez-Buelga, Beatriz Paumard-Hernández, Victoria Fernandez, Fernando Dominguez, Clara Salas, Nuria Romero-Laorden, Jesus Garcia-Donas, Jaime Carrillo, Rosario Perona, Juan Carlos Triviño, Raquel Andrés, Juana María Cano, Bárbara Rivera, Luis Alonso-Pulpon, Fernando Setien, Manel Esteller, Sandra Rodriguez-Perales, Gaelle Bougeard, Tierry Frebourg, Miguel Urioste, Maria A. Blasco, and Javier Benítez. A mutation in the pot1 gene is responsible for cardiac angiosarcoma in tp53-negative li–fraumeni-like families. Nature Communications, Sep 2015. URL: https://doi.org/10.1038/ncomms9383, doi:10.1038/ncomms9383. This article has 220 citations and is from a highest quality peer-reviewed journal.
(martinez2022amousemodel pages 1-2): Paula Martínez, Raúl Sánchez-Vázquez, Iole Ferrara-Romeo, Rosa Serrano, Juana M. Flores, and Maria A. Blasco. A mouse model for li-fraumeni-like syndrome with cardiac angiosarcomas associated to pot1 mutations. Jun 2022. URL: https://doi.org/10.1371/journal.pgen.1010260, doi:10.1371/journal.pgen.1010260. This article has 7 citations and is from a domain leading peer-reviewed journal.
(ardinger1993pot1tumorpredisposition pages 5-8): HH Ardinger and RA Pagon. Pot1 tumor predisposition. Unknown journal, 1993.
(hansford2024updateoncancer pages 1-2): Jordan R. Hansford, Anirban Das, Rose B. McGee, Yoshiko Nakano, Jack Brzezinski, Sarah R. Scollon, Surya P. Rednam, Jaclyn Schienda, Orli Michaeli, Sun Young Kim, Mary-Louise C. Greer, Rosanna Weksberg, Douglas R. Stewart, William D. Foulkes, Uri Tabori, Kristian W. Pajtler, Stefan M. Pfister, Garrett M. Brodeur, and Junne Kamihara. Update on cancer predisposition syndromes and surveillance guidelines for childhood brain tumors. Clinical cancer research : an official journal of the American Association for Cancer Research, 30:2342-2350, Apr 2024. URL: https://doi.org/10.1158/1078-0432.ccr-23-4033, doi:10.1158/1078-0432.ccr-23-4033. This article has 70 citations.
(wu2020roleofpot1 pages 5-8): Yangxiu Wu, Rebecca C. Poulos, and Roger R. Reddel. Role of pot1 in human cancer. Cancers, 12:2739, Sep 2020. URL: https://doi.org/10.3390/cancers12102739, doi:10.3390/cancers12102739. This article has 80 citations.
(webster2023germlinepot1gene pages 16-19): MD Webster. Germline pot1 gene variants in a clinical and pan-cancer cohort. Unknown journal, 2023.
(ardinger1993pot1tumorpredispositiona pages 5-8): HH Ardinger and RA Pagon. Pot1 tumor predisposition. Unknown journal, 1993.
(feldman1993pot1tumorpredisposition pages 5-7): J Feldman and GM Mirzaa. Pot1 tumor predisposition. Unknown journal, 1993.
(andreotti2024germlinepot1variants pages 5-6): Virginia Andreotti, Irene Vanni, Lorenza Pastorino, Paola Ghiorzo, and William Bruno. Germline pot1 variants: a critical perspective on pot1 tumor predisposition syndrome. Jan 2024. URL: https://doi.org/10.3390/genes15010104, doi:10.3390/genes15010104. This article has 9 citations.

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Diagnosis

Differential Diagnoses

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POT1 Tumor Predisposition Syndrome: Disease Characteristics Research Report

1. Disease information

Definition

Identifiers and synonyms

2. Etiology

Causal factor

Genetic risk factors

Environmental and protective factors

3. Phenotypes

4. Genetic and molecular information

Gene and protein

Representative germline variants

5. Environmental information

6. Mechanism and pathophysiology

Ordered causal chain

Experimental support

7. Anatomical structures affected

8. Temporal development

9. Inheritance and population

10. Diagnostics

Clinical suspicion

Molecular confirmation

Surveillance tests

11. Outcome and prognosis

12. Treatment

13. Prevention

14. Other species and natural disease

15. Model organisms and experimental systems

Human cellular models

Pot1a p.Arg117Cys knock-in mouse

Pot1b-null sarcoma model

Evidence appraisal and current expert interpretation

Artifacts

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