How is Cowden syndrome 1 inherited?

Cowden syndrome 1 follows an autosomal dominant inheritance pattern. This means inheriting just one copy of the altered gene from either parent can cause the condition.

How is Cowden syndrome 1 diagnosed?

Information about diagnosis is currently limited for this condition.

Are there treatments for Cowden syndrome 1?

Information about treatment is currently limited for this condition.

What complications can arise from Cowden syndrome 1?

Cowden syndrome 1 can lead to various tissue changes due to the PTEN gene mutation. While specific complications are still being studied, it is important for patients to be monitored regularly by healthcare providers to manage any potential issues that may develop.

How does Cowden syndrome 1 affect daily life?

Living with Cowden syndrome 1 may involve regular check-ups and monitoring for symptoms related to the condition. Patients and families might need to adapt their daily routines to include medical appointments and discussions about health management, which can impact their overall lifestyle.

What should families consider when planning for children if one parent has Cowden syndrome 1?

Since Cowden syndrome 1 is inherited through a mutation in the PTEN gene, families may want to discuss genetic counseling before planning for children. This can help them understand the risks of passing the condition to their children and explore options for family planning.

Are there specialists that should be involved in the care of someone with Cowden syndrome 1?

Yes, individuals with Cowden syndrome 1 may benefit from seeing specialists who understand the condition and its effects. This could include geneticists, oncologists, and other healthcare providers who can help monitor symptoms and provide appropriate care.

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Cowden syndrome 1 - Clinical Profile, Genes & Research | Kisho | Kisho

Rare Disease

Cowden syndrome 1

MONDO:0008021

Also known as:Cowden disease caused by mutation in PTENCowden syndrome type 1Lhermitte-Duclos syndrome

Find Clinical TrialsTrials

Overview

Any Cowden disease in which the cause of the disease is a mutation in the PTEN gene.

GeneticsAutosomal dominant · PTEN (chr 10)

Clinical Trials3 registered · 2 recruiting

Clinical Presentation

Built from Human Phenotype Ontology (HPO) phenotype annotations and GeneReviews clinical descriptions. Features represent findings documented across known cases — not an exhaustive list of possible symptoms.

Features include rarely findings: Recurrent infections, Decreased total lymphocyte count, and Decreased circulating immunoglobulin concentration. 45 total HPO annotations.

Organ System	Phenotype Count	Example Features
Brain and nerves	5	Mild intellectual disability, Seizure, Intention tremor

Genetic Landscape

Assembled from HGNC gene records, ClinGen gene-disease validity evidence, and ClinVar pathogenic variant data. Validity classifications reflect the strength of published evidence linking each gene to this disease.

PTEN function has not been fully characterized.

Cowden syndrome 1 is associated with mutations in the PTEN gene on chromosome 10.

GeneReviews

Clinical Guidance

For purposes of PTEN genotype-phenotype analyses, a series of 37 unrelated probands with CS were ascertained by the operational diagnostic criteria of the International Cowden Consortium, 1995 version . Association analyses revealed that families with CS and a germline PTEN pathogenic variant are more likely to develop malignant breast disease than are families who do not have a PTEN pathogenic variant . In addition, pathogenic missense variants and others 5' to or within the phosphatase core motif appeared to be associated with involvement of five or more organs, a surrogate phenotype for severity of disease . More than 90% of families that included individuals with CS and also individuals with BRRS were found to have a germline PTEN pathogenic variant.

Diagnosis

Drawn from GeneReviews diagnostic guidelines, newborn screening panel status (RUSP), and ClinGen gene-disease validity classifications. Reflects current clinical evidence and consensus where available.

GeneReviews

Diagnostic Criteria

Suggestive Findings

The PTEN hamartoma tumor syndrome (PHTS) includes Cowden syndrome (CS), Bannayan-Riley-Ruvalcaba syndrome (BRRS), PTEN-related Proteus syndrome (PS), and PTEN-related Proteus-like syndrome. PTEN hamartoma tumor syndrome (PHTS) should be suspected in individuals with the following clinical features.

Cowden Syndrome (CS)

Based on more than 3,000 prospectively accrued cases of CS or Cowden-like syndrome (CLS) from the community, a scoring system (which can be found online) that takes into account phenotype and age at diagnosis has been developed. The scoring system allows input of clinical information on an individual suspected of having CS/CLS and subsequently generates the prior probability of finding a PTEN pathogenic variant.

Treatment

Compiled from FDA-approved drug records, orphan drug designations, and FDA Adverse Event Reporting System (FAERS) safety data. GeneReviews management guidance is included where available.

No approved treatments are currently available for Cowden syndrome 1. The disease remains an area of unmet medical need.

GeneReviews

Management Guidelines

Evaluations and Surveillance Guidelines Following Initial Diagnosis

To establish the extent of disease and needs of an individual diagnosed with PTEN hamartoma tumor syndrome (PHTS), the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended. The most serious consequences of PHTS relate to the increased risk of cancers including breast, thyroid, endometrial, renal, and to a lesser extent, colon. In this regard, the most important aspect of management of any individual with a PTEN pathogenic variant is increased cancer surveillance to detect any tumors at the earliest, most treatable stages. Current suggested screening and surveillance by age are detailed in .

Research Landscape

Sourced from ClinicalTrials.gov and PubMed. Publication types are classified using NLM-curated article metadata; research type breakdowns reflect the nature of published work for this disease.

3 clinical trials registered, 2 recruiting. Interventions under study include other interventions and drug therapy. Pipeline includes 1 PHASE2. Research is primarily sponsored by academic and government institutions.

43 publications have been identified in PubMed for Cowden syndrome 1. Research spans Case Report / Case Series (28%), Review / Meta-Analysis (26%), and Diagnostic / Biomarker (14%).

Research Type	Count	% of Total
Patient case studies	12

Data assembled from 7 of 12 sources · Last updated Sep 19, 2026, 4:31 PM UTC

MONDOHPOClinicalTrials.govFDAPubMedHGNCClinVarClinGenGeneReviewsOrphanetOMIMRUSP

Medical References

External Resources

OMIM

Online Mendelian Inheritance in Man

OMIM:158350

GARD

Genetic and Rare Diseases Info Center

GARD:16450

Questions for Your Care Team

→Are any of the 3 active clinical trials a good fit for my situation?
→Should I pursue genetic testing for PTEN, and what would the results mean for my family?
→Are there specialists or centers of excellence for this condition in my area?
→Is there a patient registry I should consider joining?

FAQ

Frequently Asked Questions

Common questions about Cowden syndrome 1

Cowden syndrome 1 is a rare genetic condition caused by a mutation in the PTEN gene. It is one type within a group of conditions referred to as Cowden diseases, which share a common genetic basis. People with Cowden syndrome 1 may experience a range of tissue changes because of the PTEN mutation. Details about the range of symptoms and long-term features are still being studied and clarified by researchers.

Information about symptoms is currently limited for this condition.

Cowden syndrome 1 is caused by a mutation in the PTEN gene. This genetic change is the defining factor of the condition. Associated genes include PTEN.

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GeneReviews

Differential Diagnosis

Table 3. Disorders to Consider in the Differential Diagnosis of PTEN Hamartoma Tumor Syndrome

Gene(s)	Disorder	Clinical Characteristics	Comment
AKT1	AKT1-related Proteus syndrome1,2	Progressive segmental or patchy overgrowth most commonly affecting skeleton, skin, adipose tissue, CNS; development of a range of tumors, pulmonary complications, a striking predisposition to DVT pulmonary embolism	PHTS is assoc w/growth abnormalities w/linear nevi vascular malformations that are clinically molecularly distinct from those of AKT1-related Proteus syndrome. BMPR1A SMAD4
Juvenile polyposis syndrome (JPS)	Predisposition to hamartomatous polyps in GI tract (specifically stomach, small intestine, colon, rectum). Untreated polyps may cause bleeding anemia. Most juvenile polyps are benign, but malignant transformation can occur.	Unlike PHTS, polyps usually present by age 20 can reach up to 100 during a lifetime. JPS polyps are juvenile polyps by histology. PHTS polyps carry diverse histology incl epithelial overgrowth, hamartomatous, neuromatous, juvenile, adenomatous.	—
FLCN	Birt-Hogg-Dub syndrome1	Cutaneous manifestations (fibrofolliculomas, acrochordons, angiofibromas, oral papules, cutaneous collagenomas, epidermal cysts), pulmonary cysts / history of pneumothorax, various types of renal tumors	Cutaneous lesions can be mistaken for trichilemmomas characteristic of PHTS. Unlike the predominant papillary renal cancers in PHTS, BHD renal cancers have a mixed chromophobe/oncocytic histology.
NF1	Neurofibromatosis type 1 (NF1)1	The only features seen in both NF1 CS/BRRS are caf au lait macules fibromatous tumors of the skin.	NF1 may be mistakenly diagnosed in persons w/CS/BRRS due to presence of ganglioneuromas in GI tract. PTCH1
SUFU	Nevoid basal cell carcinoma syndrome (NBCCS)1	Multiple jaw keratocysts /or basal cell carcinomas; skeletal anomalies; ectopic calcification; in ~60% of persons, a recognizable appearance w/macrocephaly, frontal bossing, coarse facial features, facial milia	Dermatologic findings developmental features in CS NBCCS are quite different. STK11
Peutz-Jeghers syndrome	GI polyposis, mucocutaneous pigmentation, cancer predisposition	The P-J polyp has a diagnostic appearance is quite different from CS or JPS hamartomatous polyps. P-J polyps are often symptomatic (intussusception, rectal bleeding); CS polyps are rarely so.	—

Source: GeneReviews — "PTEN Hamartoma Tumor Syndrome"

Kisho

Cowden syndrome 1

Overview

Clinical Presentation

Genetic Landscape

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Cowden Syndrome (CS)

Treatment

Management Guidelines

Evaluations and Surveillance Guidelines Following Initial Diagnosis

Research Landscape

Medical References

External Resources

OMIM

GARD

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

Clinical Guidance

Explore clinical features

Penetrance

Differential Diagnosis

General

Breast (female)

Clinical Guidance

Therapies Under Investigation

Clinical Trials

Recent Publications

Cowden syndrome 1

Overview

Clinical Presentation

Genetic Landscape

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Cowden Syndrome (CS)

Treatment

Management Guidelines

Evaluations and Surveillance Guidelines Following Initial Diagnosis

Research Landscape

Medical References

External Resources

OMIM

GARD

Related Diseases

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

What is Cowden syndrome 1?

What are the symptoms of Cowden syndrome 1?

What causes Cowden syndrome 1?

How is Cowden syndrome 1 inherited?

How is Cowden syndrome 1 diagnosed?

Are there treatments for Cowden syndrome 1?

What complications can arise from Cowden syndrome 1?

How does Cowden syndrome 1 affect daily life?

What should families consider when planning for children if one parent has Cowden syndrome 1?

Are there specialists that should be involved in the care of someone with Cowden syndrome 1?

Clinical Guidance

Explore clinical features

Penetrance

Differential Diagnosis

General

Breast (female)

Clinical Guidance

Therapies Under Investigation

Clinical Trials

Recent Publications