Cowden syndrome


Cowden syndrome is a rare genetic disorder characterized by the development of multiple noncancerous growths called hamartomas. These growths tend to develop on the skin and mucous membranes, including the lining of the nose and mouth, as well as in other parts of the body, such as the digestive tract. Other signs and symptoms of Cowden syndrome can include an enlarged head and a rare, noncancerous brain tumor called Lhermitte-Duclos disease.
About 85% of Cowden syndrome cases are caused by mutations or defects in the PTEN gene. The causes of the remaining cases are unknown. PTEN is a tumor suppressor gene that encodes for the PTEN protein, which normally prevents cells from growing and dividing too rapidly or in an uncontrolled way. Uncontrolled cell division can lead to the formation of hamartomas and cancerous tumors. Mutations in the PTEN gene have been identified in about 85% of people with Cowden syndrome.
Cowden syndrome is inherited, or passed down among family members, as an autosomal dominant trait. Individuals inherit two copies of most genes, one from the mother and one from the father. To inherit an autosomal dominant trait, only one copy of the defective PTEN gene needs to be inherited. Some cases of Cowden syndrome occur in individuals with no family history of the disease. This is the result of a spontaneous genetic mutation in the egg, sperm cells, or developing embryo.
Cowden syndrome affects about one in 200,000 people worldwide. There have been reports of about 300 cases in the scientific literature. Males and females are affected in equal numbers. Males are more likely to develop certain complications such as thyroid cancer, while females are more likely to develop breast cancer. This syndrome appears to affect people of all races and ethnicities equally.
Individuals with Cowden syndrome may have nearly normal life spans. Abnormal growths on the skin and mucous membranes typically appear by the late twenties, although the age at onset of clinical manifestations of Cowden syndrome varies, ranging from birth to 46 years. While these growths may be benign, individuals with Cowden syndrome are at an increased risk of developing several types of cancer, including cancers of the breast, thyroid, and uterus. Most common complications arise from cancerous tumors. About 40% of people with Cowden syndrome develop at least one cancerous tumor. When detected early, many of these cancers are treatable. Cowden syndrome is primarily associated with increased frequency of malignant, or cancerous, tumors. Benign, or noncancerous, tumors in patients with Cowden syndrome also can cause significant illness.

Related Terms

BMPR1A gene, breast cancer, Cowden's disease, Cowden's syndrome, CS, hamartoma, MHAM, MMAC1 gene, multiple hamartoma syndrome, PTEN gene, TEP1 gene, thyroid cancer.