Barraquer–Simons syndrome
Rare lipodystrophy affecting head and thorax.
Barraquer–Simons syndrome, also called acquired partial lipodystrophy (APL), is a rare condition in which subcutaneous fat is lost in a symmetrical, gradual pattern. The fat loss begins on the face, then moves downward to the neck, upper arms, chest, and abdomen, while the legs and buttocks are usually spared—and may even gain fat, especially in women. The palms can lose some fat, but the bone marrow and area behind the eyes are not affected. The syndrome is named after Spanish physician Luis Barraquer Roviralta and German physician Arthur Simons. Some evidence links it to the LMNB2 gene.
The exact cause is not fully understood. Lipodystrophy in this syndrome often occurs alongside glomerulonephritis, low levels of the complement protein C3, and a substance called C3 nephritic factor (C3NeF). C3NeF is an immunoglobulin G that activates the alternative complement pathway, which may destroy fat cells that secrete adipsin—a protein identical to complement factor D. The pattern of fat loss is thought to depend on how much adipsin different fat deposits produce. Mutations in the PTRF gene can lead to a shortage of caveolins, causing generalized lipodystrophy along with muscular dystrophy. Complement problems may also raise the risk of bacterial infections.
Diagnosis is mainly based on clinical signs. A 2004 review of 35 patients and 220 published cases proposed that APL typically starts around age seven and follows a head-to-toe (cephalocaudal) pattern. Many patients also have autoimmune diseases like lupus or dermatomyositis. About 6.7% develop diabetes, and 8.9% have impaired glucose tolerance. Low C3 levels and C3NeF are found in roughly 83% of patients. Around 22% develop membranoproliferative glomerulonephritis (MPGN) about eight years after the lipodystrophy begins. Those with MPGN tend to have an earlier onset of fat loss (average 7.7 years vs. 12.6 years) and are more likely to have low C3 (95% vs. 78%).
Lab tests are used to check for related metabolic, autoimmune, and kidney problems. At the first visit, patients should have fasting blood glucose, a lipid panel, creatinine, and a urine test for protein, and these should be repeated regularly. While uncommon, high triglycerides and low HDL cholesterol can occur. Serum C3 is usually low, while C1 and C4 are normal, and C3NeF is high—which may signal kidney involvement.
Quick Facts
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- endocrinology
Facts from the source article.
Lore & Background
Luis Barraquer Roviralta was a Spanish physician active in the late 19th and early 20th centuries. Arthur Simons was a German physician whose work overlapped with Barraquer's in describing the syndrome that now bears both their names. The condition they identified is a rare form of lipodystrophy, with around 250 cases reported since its recognition.
The syndrome is characterized by gradual, bilaterally symmetrical loss of subcutaneous fat starting in the face and progressing downward to the neck, upper extremities, thorax, and abdomen, while fat in the gluteal regions and lower extremities tends to be preserved or increased. The median age of onset is about seven years, and women are affected about four times more often than men.
Some evidence links the syndrome to LMNB2. The etiology has not been fully elucidated, but it is often associated with glomerulonephritis, low C3 serum complement levels, and the presence of a C3 nephritic factor, which is a serum immunoglobulin G that interacts with the C3bBb alternative pathway convertase to activate C3.
Reader's Guide
Barraquer–Simons syndrome is significant as a rare lipodystrophy with distinctive clinical features and associated complications. Diagnosis is primarily clinical, based on the characteristic pattern of fat loss, with laboratory workup needed to investigate associated metabolic, autoimmune, and renal diseases. Key laboratory findings include decreased serum C3 levels, normal C1 and C4 levels, and high levels of C3 nephritic factor, which may indicate renal involvement.
The condition carries substantial morbidity due to associated autoimmune diseases (such as systemic lupus erythematosus and dermatomyositis) and the development of membranoproliferative glomerulonephritis (MPGN) in about 22% of patients, typically about eight years after onset of lipodystrophy. About 40-50% of patients with MPGN develop end-stage renal disease over ten years. No effective treatment exists to halt progression of the lipodystrophy itself; management focuses on cosmetic options (such as facial implants), dietary therapy, and treatment of associated conditions like renal dysfunction and metabolic abnormalities. The syndrome is more common than the generalized form of acquired lipodystrophy (Lawrence syndrome).
Did You Know?
- The median age of onset of lipodystrophy in Barraquer–Simons syndrome is about seven years.
- Around 83% of patients have low complement 3 (C3) levels and the presence of polyclonal immunoglobulin C3 nephritic factor.
- About 22% of patients develop membranoproliferative glomerulonephritis after a median of about eight years following the onset of lipodystrophy.
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