Barraquer–Simons syndrome is a rare form of lipodystrophy,
which usually first affects the head, and then spreads to the thorax. It is named for Luis Barraquer Roviralta (1855–1928), a Spanish physician, and Arthur Simons (1879–1942), a German physician. Some evidence links it to LMNB2. Causes
The etiology of this condition has not been fully elucidated. Lipodystrophy is often associated with glomerulonephritis, low C3 serum complement levels, and the presence of a C3 nephritic factor. C3 nephritic factor is a serum immunoglobulin G that interacts with the C3bBb alternative pathway convertase to activate C3. C3 nephritic factor induces the lysis of adipocytes that secrete adipsin, a product identical to complement factor D. The distribution of the lipoatrophy is postulated to be dictated by the variable amounts of adipsin secreted by the adipocytes at different locations.Human PTRF mutations may cause secondary deficiency of caveolins, resulting in generalized lipodystrophy in association with in muscular dystrophy. Complement dysfunction may predispose some patients to bacterial infections. Diagnosis
The diagnosis of the disease is mainly clinical (see diagnostic criteria). A laboratory workup is needed primarily to investigate for the presence of associated disorders (metabolic, autoimmune, and renal diseases). Every patient should have a fasting blood glucose and lipid profile, creatinine evaluation, and urinalysis for protein content at the first visit, after which he/she should have these tests on a regular basis. Although uncommon, lipid abnormalities can occur in the form of raised triglyceride levels and low high-density lipoprotein cholesterol levels.
Patients usually have decreased serum C3 levels, normal levels of C1 and C4, and high levels of C3NeF (autoantibody), which may indicate the presence of renal involvement. Antinuclear antibodies (ANA) and antidouble-stranded deoxyribonucleic acid (DNA) antibodies have reportedly been observed in some patients with acquired partial lipodystrophy. A genetic workup should be performed if the familial form of lipodystrophy is suggested.Laboratory work for associated diseases includes:
Metabolic disease - fasting glucose, glucose tolerance test, lipid profile, and fasting insulin to characterize the insulin resistance state; free testosterone (in women) to look for polycystic ovary syndrome. Autoimmune disease - ANA, antidouble-stranded DNA, rheumatoid factor, thyroid antibodies, C3, and C3NeF.As a confirmatory test, whole-body MRI usually clearly demonstrates the extent of lipodystrophy. MRI is not recommended on a routine basis. Diagnostic criteria
A review published in 2004, which was based on 35 patients seen by the respective authors over 8 years and also a literature review of 220 cases of acquired partial lipodystrophy (APL), proposed an essential diagnostic criterion. Based on the review and the authors experience, they proposed that APL presents as a gradual onset of bilaterally symmetrical loss of subcutaneous fat from the face, neck, upper extremities, thorax, and abdomen, in the "cephalocaudal" sequence, sparing the lower extremities. The median age of the onset of lipodystrophy was seven years. Several autoimmune diseases, in particular systemic lupus erythematosus and dermatomyositis, were associated with APL. The prevalence rates of diabetes mellitus and impaired glucose tolerance were 6.7% and 8.9%, respectively.