The
lipodystrophies are rare disorders characterized by selective but variable loss of adipose tissue. Metabolic complications, such as
insulin resistance,
diabetes mellitus,
hypertriglyceridemia, and
fatty liver, increase in severity with the extent of fat loss. The
lipodystrophies can be classified into two major types: familial and acquired. The main subtypes of familial
lipodystrophies are
congenital generalized lipodystrophy, an autosomal recessive disorder characterized by near complete lack of metabolically active adipose tissue from birth, and
familial partial lipodystrophy, Dunnigan type, an autosomal dominant disorder characterized by loss of subcutaneous fat from the extremities at puberty and excess fat accumulation in the face and neck. Recently, a gene for
congenital generalized lipodystrophy was localized to chromosome 9q34, and a gene for
familial partial lipodystrophy, Dunnigan type, to chromosome 1q21-22; the genes, however, remain to be identified. Patients with acquired
generalized lipodystrophy have generalized loss of subcutaneous fat, but those with
acquired partial lipodystrophy have fat loss limited to the face, trunk, and upper extremities. Both varieties occur approximately three times more often in women, begin during childhood, and have underlying autoimmunity. Patients infected with the human immunodeficiency virus (HIV) who are receiving
therapy that includes
HIV-1 protease inhibitors have been reported to develop a
lipodystrophy characterized by loss of subcutaneous fat from the extremities and face but excess fat deposition in the neck and trunk. Localized
lipodystrophies can be caused by drugs, pressure,
panniculitis, or unknown mechanisms. Current management of patients includes cosmetic surgery, diet, and
drug therapy for control of diabetes and
dyslipidemia.