CDH1 Gene

Hereditary diffuse gastric cancer (HDGC) is an inherited disorder that greatly increases the chance of developing a form of stomach(gastric) cancer. In this form, known as diffuse gastric cancer, there is no solid tumor. Instead cancerous (malignant) cells multiply underneath the stomach lining, making the lining thick and rigid. The invasive nature of this type of cancer makes it highly likely that these cancer cells will spread (metastasize) to other tissues, such as the liver or nearby bones.

Symptoms of diffuse gastric cancer occur late in the disease and can include stomach pain, nausea, vomiting, difficulty swallowing (dysphagia), decreased appetite, and weight loss. If the cancer metastasizes to other tissues, it may lead to an enlarged liver, yellowing of the eyes and skin (jaundice), an abnormal buildup of fluid in the abdominal cavity (ascites), firm lumps under the skin, or broken bones.

In HDGC, gastric cancer usually occurs in a person's late thirties or early forties, although it can develop anytime during adulthood. If diffuse gastric cancer is detected early, the survival rate is high; however, because this type of cancer is hidden underneath the stomach lining, it is usually not diagnosed until the cancer has become widely invasive. At that stage of the disease, the survival rate is approximately 20 percent.

Some people with HDGC have an increased risk of developing other types of cancer, such as a form of breast cancer in women that begins in the milk-producing glands (lobular breast cancer); prostate cancer; and cancers of the colon (large intestine) and rectum, which are collectively referred to as colorectal cancer. Most people with HDGC have family members who have had one of the types of cancer associated with HDGC. In some families, all the affected members have diffuse gastric cancer. In other families, some affected members have diffuse gastric cancer and others have another associated form of cancer, such as lobular breast cancer. Frequently, HDGC-related cancers develop in individuals before the age of 50.

Blepharocheilodontic (BCD) syndrome is a disorder that is present at birth. It mainly affects the eyelids (blepharo-), upper lip (-cheilo-), and teeth (-dontic).

People with BCD syndrome have lower eyelids that turn out so that the inner surface is exposed (ectropion). The outside of the lower lid may sag away from the eye (euryblepharon), and the eyelids may not be able to close completely (lagophthalmia). There can be extra eyelashes (distichiasis) on the upper eyelids, ranging from a few extra eyelashes to a full extra set. These eyelashes do not grow along the edge of the eyelid with the normal lashes, but out of its inner lining. When the abnormal eyelashes touch the eyeball, they can cause damage to the clear covering of the eye (cornea). Affected individuals may also have widely spaced eyes (hypertelorism), a flat face, and a high forehead.

Other features of BCD syndrome usually include openings on both sides of the upper lip (bilateral cleft lip) and an opening in the roof of the mouth (cleft palate). Affected individuals may have fewer teeth than normal (oligodontia) and their teeth are often smaller than usual and cone-shaped. The dental abnormalities affect both primary teeth (sometimes called "baby teeth") and secondary (permanent) teeth. Other frequent features include sparse, fine hair and abnormal nails.

Occasionally people with BCD syndrome have additional features, including an obstruction of the anal opening (imperforate anus); malformation or absence of the butterfly-shaped gland in the lower neck called the thyroid, resulting in lack of thyroid gland function; or fused fingers or toes (syndactyly). Very rarely, affected individuals have incompletely formed arms or legs (limb reduction defects) or a spinal cord abnormality known as spina bifida.

Breast cancer is a disease in which certain cells in the breast become abnormal and multiply uncontrollably to form a tumor. Although breast cancer is much more common in women, this form of cancer can also develop in men. In both women and men, the most common form of breast cancer begins in cells lining the milk ducts (ductal cancer). In women, cancer can also develop in the glands that produce milk (lobular cancer). Most men have little or no lobular tissue, so lobular cancer in men is very rare.

In its early stages, breast cancer usually does not cause pain and may exhibit no noticeable symptoms. As the cancer progresses, signs and symptoms can include a lump or thickening in or near the breast; a change in the size or shape of the breast; nipple discharge, tenderness, or retraction (turning inward); and skin irritation, dimpling, redness, or scaliness. However, these changes can occur as part of many different conditions. Having one or more of these symptoms does not mean that a person definitely has breast cancer.

In some cases, cancerous cells can invade surrounding breast tissue. In these cases, the condition is known as invasive breast cancer. Sometimes, tumors spread to other parts of the body. If breast cancer spreads, cancerous cells most often appear in the bones, liver, lungs, or brain. Tumors that begin at one site and then spread to other areas of the body are called metastatic cancers.

A small percentage of all breast cancers cluster in families. These cancers are described as hereditary and are associated with inherited gene mutations. Hereditary breast cancers tend to develop earlier in life than noninherited (sporadic) cases, and new (primary) tumors are more likely to develop in both breasts.