Familial partial lipodystrophy is a rare condition characterized by an abnormal distribution of fatty (adipose) tissue. Adipose tissue is normally found in many parts of the body, including beneath the skin and surrounding the internal organs. It stores fat as a source of energy and also provides cushioning. In people with familial partial lipodystrophy, adipose tissue is lost from the arms, legs, and hips, giving these parts of the body a very muscular appearance. The fat that cannot be stored in the limbs builds up around the face and neck, and inside the abdomen. Excess fat in these areas gives individuals an appearance described as "cushingoid," because it resembles the physical features associated with a hormonal disorder called Cushing disease. This abnormal fat distribution can begin anytime from childhood to adulthood.
Familial partial lipodystrophy can be caused by mutations in several genes. Type 2 results from mutations in the LMNA gene. The other, less common forms of the disorder are caused by mutations in different genes.
Familial partial lipodystrophy is a rare disease, affecting an estimated 1 in 1 million people overall. Type 2 is the most common form, with more than 500 cases reported in the medical literature. Women tend to be diagnosed with familial partial lipodystrophy more often than men, probably because a loss of fat from the hips and limbs is more easily recognized in women, and complications such as diabetes and hypertriglyceridemia occur more commonly in women.
Most cases of familial partial lipodystrophy, including type 2, are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
Published Date: September 01, 2016Published By: National Institutes of Health