Dictionary

gene, target The primary gene of concern. See also gene, marker.

gene, evolutionarily conserved A gene that has remained essentially unchanged throughout evolution. Conservation of a gene indicates that it is unique and essential. Changes in the gene are likely to be lethal.

gene, breast cancer susceptibility See breast cancer susceptibility gene.

gene 1 In classical genetics, a unit of inheritance. 2 In molecular genetics, a sequence of chromosomal DNA that is required to make a functional product.

gender identity disorder See transsexualism.

Gaucher disease A series of disorders that are due to deficient activity of the enzyme glucocerebrosidase, which leads to accumulation of glucocerebroside in tissues of the body. The five types of Gaucher disease encompass a continuum of clinical findings from a lethal form that occurs before or just after birth to a form so mild…

gastrostomy, percutaneous endoscopic A surgical procedure for placing a feeding tube that does not necessitate performing an open laparotomy operation on the abdomen. Abbreviated PEG. An endoscope is passed through the mouth, throat, and esophagus to the stomach. The surgeon then makes a small incision in the skin of the abdomen, pushes an IV tube…

gastrostomy A surgical opening into the stomach. A gastrostomy may be used for feeding, usually via a feeding tube called a gastrostomy tube. Feeding can also be done through a percutaneous endoscopic gastrostomy (PEG) tube.

gastroscope A flexible, lighted instrument that is put through the mouth and esophagus to view the stomach. Tissue from the stomach can be removed through a gastroscope.

gastroparesis A disease of the muscles of the stomach or the nerves controlling the muscles that causes the muscles to stop working. Gastroparesis results in inadequate grinding of food by the stomach and poor emptying of food from the stomach into the intestine. Gastroparesis may be associated with paralysis of the small intestine and colon….

gastrointestinal tract The stomach and intestines. Abbreviated GI tract.

gastrointestinal stromal tumor A type of tumor that usually begins in cells in the wall of the gastrointestinal tract. It can be benign or malignant. Abbreviated GIST. Malignant GISTs can occur from the esophagus to the rectum, but occur most commonly in the stomach and small intestine. Treatment for GIST includes STI571 (Gleevec), the first…