Question: What is (are) Cowden syndrome ?
Answer: Cowden syndrome is an inherited condition that is characterized primarily by multiple, noncancerous growths (called hamartomas) on various parts of the body. It is considered part of the PTEN Hamartoma Tumor Syndrome spectrum which also includes Bannayan-Riley-Ruvalcaba syndrome and Proteus syndrome. People affected by Cowden syndrome are also at an increased risk of developing certain types of cancer, such as breast, thyroid and endometrial (lining of the uterus) cancer. Most cases are caused by changes (mutations) in the PTEN gene and are inherited in an autosomal dominant manner. Management typically includes high-risk screening for associated tumors and/or prophylactic surgeries.
Source: GARD

Question: What are the symptoms of Cowden syndrome ?
Answer: What are the signs and symptoms of Cowden syndrome? Cowden syndrome is characterized primarily by multiple, noncancerous growths (called hamartomas) on various parts of the body. Approximately 99% of people affected by Cowden syndrome will have benign growths on the skin and/or in the mouth by the third decade of life. A majority of affected people will also develop growths (called hamartomatous polyps) along the inner lining of the gastrointestinal tract. People affected by Cowden syndrome also have an increased risk of developing certain types of cancer. Breast, thyroid and endometrial (the lining of the uterus) cancers are among the most commonly reported tumors. Other associated cancers include colorectal cancer, kidney cancer and melanoma. People with Cowden syndrome often develop cancers at earlier ages (before age 50) than people without a hereditary predisposition to cancer. Other signs and symptoms of Cowden syndrome may include benign diseases of the breast, thyroid, and endometrium; a rare, noncancerous brain tumor called Lhermitte-Duclos disease; an enlarged head (macrocephaly); autism spectrum disorder; intellectual disability; and vascular (the body's network of blood vessels) abnormalities. The Human Phenotype Ontology provides the following list of signs and symptoms for Cowden syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormality of the pupil 90% Abnormality of the tongue 90% Aplasia/Hypoplasia of the cerebellum 90% Arteriovenous malformation 90% Cognitive impairment 90% Conjunctival hamartoma 90% Dental malocclusion 90% Epibulbar dermoid 90% Exostoses 90% Foot polydactyly 90% Genu recurvatum 90% Incoordination 90% Increased intracranial pressure 90% Intestinal polyposis 90% Irregular hyperpigmentation 90% Lower limb asymmetry 90% Macrocephaly 90% Melanocytic nevus 90% Migraine 90% Myopia 90% Nausea and vomiting 90% Neoplasm of the breast 90% Neoplasm of the nervous system 90% Neoplasm of the thyroid gland 90% Seizures 90% Uterine neoplasm 90% Verrucae 90% Abnormality of the parathyroid gland 50% Abnormality of the penis 50% Abnormality of the teeth 50% Anemia 50% Cataract 50% Cavernous hemangioma 50% Communicating hydrocephalus 50% Dolichocephaly 50% Furrowed tongue 50% Gastrointestinal hemorrhage 50% Gingival overgrowth 50% Goiter 50% Heterochromia iridis 50% Hypermelanotic macule 50% Hyperostosis 50% Hypertrichosis 50% Mandibular prognathia 50% Meningioma 50% Mucosal telangiectasiae 50% Multiple lipomas 50% Palmoplantar keratoderma 50% Retinal detachment 50% Shagreen patch 50% Venous insufficiency 50% Intellectual disability 12% Intellectual disability, mild 12% Abnormality of neuronal migration 7.5% Abnormality of the palate 7.5% Abnormality of the retinal vasculature 7.5% Adenoma sebaceum 7.5% Anteverted nares 7.5% Autism 7.5% Bone cyst 7.5% Brachydactyly syndrome 7.5% Bronchogenic cyst 7.5% Cafe-au-lait spot 7.5% Gynecomastia 7.5% Hearing impairment 7.5% Hypopigmented skin patches 7.5% Kyphosis 7.5% Melanoma 7.5% Ovarian neoplasm 7.5% Pectus excavatum 7.5% Polycystic ovaries 7.5% Renal neoplasm 7.5% Scoliosis 7.5% Short stature 7.5% Skeletal dysplasia 7.5% Splenomegaly 7.5% Tall stature 7.5% Thymus hyperplasia 7.5% Abnormality of the cardiovascular system - Adult onset - Angioid streaks of the retina - Autosomal dominant inheritance - Breast carcinoma - Colonic diverticula - Fibroadenoma of the breast - Hamartomatous polyposis - High palate - Hydrocele testis - Hyperthyroidism - Hypoplasia of the maxilla - Hypothyroidism - Intention tremor - Narrow mouth - Ovarian cyst - Palmoplantar hyperkeratosis - Progressive macrocephaly - Skin tags - Subcutaneous lipoma - Thyroid adenoma - Thyroiditis - Transitional cell carcinoma of the bladder - Varicocele - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes Cowden syndrome ?
Answer: What causes Cowden syndrome? Most cases of Cowden syndrome are caused by changes (mutations) in the PTEN gene. PTEN is a tumor suppressor gene which means that it encodes a protein that helps keep cells from growing and dividing too rapidly or in an uncontrolled way. Mutations in PTEN result in a defective protein that is unable to carry out its normal role. This leads to the development of the various tumors and cancers associated with Cowden syndrome. Rarely, Cowden syndrome is caused by mutations in KLLN, SDHB, SDHC, SDHD, PIK3CA or AKT1. Some affected families have no identifiable mutation in any of the genes associated with Cowden syndrome; in these families, the exact underlying cause is unknown.
Source: GARD

Question: Is Cowden syndrome inherited ?
Answer: How is Cowden syndrome inherited? Cowden syndrome is inherited in an autosomal dominant manner. This means that to be affected, a person only needs a change (mutation) in one copy of the responsible gene in each cell. In some cases, an affected person inherits the mutation from an affected parent. Other cases may result from new (de novo) mutations in the gene. These cases occur in people with no history of the disorder in their family. A person with Cowden syndrome has a 50% chance with each pregnancy of passing along the altered gene to his or her child.
Source: GARD

Question: How to diagnose Cowden syndrome ?
Answer: How is Cowden syndrome diagnosed? A diagnosis of Cowden syndrome is based on the presence of characteristic signs and symptoms. Genetic testing for a change (mutation) in the PTEN gene can then be ordered to confirm the diagnosis. If a mutation in PTEN is not identified, genetic testing for the other genes known to cause Cowden syndrome can be considered. GeneReviews offers more detailed information regarding the diagnosis of Cowden syndrome including the clinical diagnostic criteria. Click here to view this resource. The PTEN Cleveland Clinic Risk Calculator can be used to estimate the chance of finding a PTEN mutation in children and adults with signs and symptoms of Cowden syndrome. Is genetic testing available for Cowden syndrome? Yes, genetic testing is available for many of the genes known to cause Cowden syndrome. Carrier testing for at-risk relatives and prenatal testing are possible if the disease-causing mutation in the family is known. The Genetic Testing Registry (GTR) is a centralized online resource for information about genetic tests. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Source: GARD