Several rare conditions are associated with loss of fatty tissue in a partial or generalized distribution.
Partial Lipodystrophy. Partial lipodystrophy may be familial or acquired. Loss of adipose tissue is not preceded by an inflammatory phase, and histopathologic examination reveals only absence of subcutaneous fat.
There are 3 forms of familial partial lipodystrophy (FPLD).
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Type I (FPLD1-Kobberling) is characterized by loss of adipose tissue confined to the extremities and gluteal region. Fat distribution of the face, neck, and trunk may be normal or increased. Hyperlipidemia, insulin-resistant diabetes mellitus, and eruptive xanthomas may be seen. The gene is unknown, but only females are affected. |
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Type 2 (FPLD2-Dunnigan) is caused by mutations in the laminin A/C gene. Fat distribution is normal in childhood, but atrophy commences with puberty. Lipodystrophy is seen in the trunk, gluteal region, and extremities. Adipose tissue accumulates in the face and neck and may also be seen in the axillae, back, labia majora, and infra-abdominal region. Insulin-resistant diabetes mellitus and hypertriglyceridemia develop, but high-density lipoprotein and cholesterol levels are low. Both males and females are affected, but the diagnosis may be more difficult in males due to body habitus. |
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Type 3 (FPLD3) is caused by mutations in the peroxisome proliferation–activated receptor gamma (PPARG) gene. Lipodystrophy is seen in the limbs and gluteal region. Insulin-resistant diabetes mellitus, primary amenorrhea, acanthosis nigricans, hypertension, and fatty infiltration of the liver are present. |
Acquired partial lipodystrophy (Barraquer-Simons syndrome) is rare. Females are more commonly affected. Fat loss begins in childhood or adolescence and affects the face, neck, arms, thorax, and upper abdomen. Excess fat is seen in the hips and legs, especially in females. Low levels of C3 are almost universally seen. C3 nephritic factor is also present. C3 nephritic factor stabilizes C3 convertase, allowing for unopposed activation of the alternate complement pathway Continue reading »
Several rare conditions are associated with loss of fatty tissue in a partial or generalized distribution.
