Congenital generalized lipodystrophy

Other Names: Brunzell syndrome; BSCL; GCL; Lipoatrophic diabetes; Berardinelli-Seip syndrome; Beradinelli-Seip syndrome; Generalized congenital lipodystrophy; Berardinelli-Seip congenital lipodystrophy

Congenital generalized lipodystrophy is a rare disease characterized by a generalized lack of fat (adipose tissue) in the body. It is part of a group of diseases known as lipodystrophies.

Signs and symptoms

Signs and symptoms are noticed from birth (congenital) or early childhood and include high levels of fats (triglycerides) in the blood (hypertriglyceridemia) and insulin resistance (in which the body tissues are unable to respond to the hormone insulin that helps to regulate blood sugar levels) resulting in diabetes mellitus, abnormal accumulation of fat in the liver (liver steatosis) and the accumulation of fat in the heart causing a thickening of the heart muscle (hypertrophic cardiomyopathy), which can lead to a heart that does not work well (heart failure) and sudden death. Due to the almost total absence of fatty tissue and excessive growth of muscle tissue, the patients appear very muscular and have visible and prominent veins. They also have dark and thick skin in the body folds (acanthosis nigricans). For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Accelerated skeletal maturation(Advanced bone age)
• Broad foot(Broad feet)
• Hepatomegaly(Enlarged liver)
• Hyperinsulinemia
• Hypertriglyceridemia(Increased plasma triglycerides)
• Insulin resistance(Body fails to respond to insulin)
• Large hands(large hand)
• Lipoatrophy(Loss of fat tissue in localized area)
• Mandibular prognathia(Big lower jaw)
• Prominent supraorbital ridges(Prominent brow)
• Skeletal muscle hypertrophy(Increased skeletal muscle cells)

Cause

Congenital generalized lipodystrophy is caused by mutations in AGPAT2 gene,BSCL2 gene,CAV1 gene,CAVIN1 gene

Types

There are 4 types of the disease that are distinguished by the altered (mutated) genes and by some additional characteristic symptoms. People with type 1, caused by mutations in the AGPAT2 gene, may have cysts in the long bones of the arms and the legs after puberty. In type 2, which is caused by mutations in the BSCL2 gene, there may be intellectual disability. In type 3, caused by mutations in the CAV1 gene, affected people may have short stature and growth delay. Type 4, caused by mutations in the CAVIN1 gene, is associated with muscle weakness, developmental delay, joint anomalies, narrowing of the lower part of the stomach (pyloric stenosis), and severe heart arrhythmia that can lead to sudden death.

Inheritance

Autosomal recessive inheritance, a 25% chance

The inheritance of Berardinelli-Seip congenital lipodystrophy is autosomal recessive.

Diagnosis

Physical diagnosis of CGL is easier, as CGL patients are recognizable from birth, due to their extreme muscular appearance, which is caused by the absence of subcutaneous fat. Medical diagnosis of CGL can be made after observing the physical symptoms of the disease: lipoatrophy (loss of fat tissues) affecting the trunk, limbs, and face; hepatomegaly; acromegaly; insulin resistance; and high serum levels of triglycerides. Genetic testing can also confirm the disease, as mutations in the AGPAT2 gene is indicative of CGL1, a mutation in the BSCL2 gene is indicative of CGL2, and mutations in the CAV1 and PTRF genes are indicative of CGL3 and CGL4 respectively CGL3 patients have serum creatine kinase concentrations much higher than normal (2.5 to 10 times the normal limit). This can be used to diagnose type 3 patients and differentiate them from CGL 1 and 2 without mapping their genes. Additionally, CGL3 patients have low muscle tone when compared with other CGL patients.

Treatment

Treatment consists on a fat restricted diet and diabetes control, and may also include leptin administration.

Metformin is the main drug used for treatment, as it is normally used for patients with hyperglycemia.

Metformin reduces appetite and improves symptoms of hepatic steatosis and polycystic ovary syndrome.

Leptin can also be used to reverse insulin resistance and hepatic steatosis, to cause reduced food intake, and decrease blood glucose levels.

Diet

CGL patients have to maintain a strict diet for life, as their excess appetite will cause them to overeat. Carbohydrate intake should be restricted in these patients. To avoid chylomicronemia, CGL patients with hypertriglyceridemia need to have a diet very low in fat. CGL patients also need to avoid total proteins, trans fats, and eat high amounts of soluble fiber to avoid getting high levels of cholesterol in the blood.

NIH genetic and rare disease info

• NIH info on Congenital generalized lipodystrophy

Congenital generalized lipodystrophy is a rare disease.

Congenital generalized lipodystrophy Resources
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