Dictionary

goiter A noncancerous enlargement of the thyroid gland. With a goiter, the levels of thyroid hormones may be normal (euthyroid), elevated (hyperthyroidism), or decreased (hypothyroidism).

GM2-gangliosidosis One of a group of genetic lipid storage disorders that affect the brain. The main types of GM2 gangliosidoses are Tay-Sachs disease and its variants (due to hexosaminidase A deficiency) and Sandhoff disease and its variants (due to hexosaminidase B deficiency). See also Sandhoff disease; Tay-Sachs disease.

GM1-gangliosidosis A rare genetic lipid storage disorder that is similar to Hurler syndrome and TaySachs disease but that affects both the brain and the viscera. Symptoms include skeletal deformities and severe effects on the brain and organs. The mutation that is responsible for the disease is located on chromosome 3. There is no treatment for…

glycosaminoglycan A negatively charged chain of polysaccharides (modified sugars) that is composed of repeating disaccharide units. Abbreviated GAG. Important GAGs in the human body include chondroitin sulfate, dermatan sulfate, heparan sulfate, heparin, hyaluronate, and keratan sulfate. GAGs are involved as lubricants and components of bone, cartilage, blood vessels, and certain types of cells. Also known…

glycogen storage disease One of the multiple inherited disorders of metabolism that interfere with glycogen synthesis or breakdown, leading to the storage of carbohydrates as glycogen in the body. The conditions may affect the liver or the skeletal (striated) muscle, both primary glycogen storage sites. Symptoms and signs depend upon the exact type but can…

glycemic index An indicator of the rapidity and extent to which carbohydrate-containing foods raise the blood glucose levels in the two hours after consumption. Foods containing carbohydrates that break down most quickly during digestion have the highest glycemic index. Also called the dietary glycemic index. See also glucose.

gluten enteropathy See celiac sprue.

gluten A protein that is found in wheat and related grains. Gluten can be found in a large variety of processed foods, including soups, salad dressings, and natural flavorings. Unidentified starches, hydrolyzed proteins, and binders and fillers used in medications or vitamins can be unsuspected sources of gluten. People with celiac sprue, Crohn’s disease, or…

gluteal Pertaining to the buttocks region, which is formed by the gluteus maximus, gluteus medius, and gluteus minimus muscles.

glucuronosyltransferase, UDP- A liver enzyme that is essential to the disposal of bilirubin. An abnormality of UDP-glucuronosyltransferase results in a condition called Gilbert syndrome. See also Gilbert syndrome.

glucosylceramidosis See Gaucher disease.

glucose-6-phosphate dehydrogenase See G6PD.