Dunnigan syndrome is belongs to the group of partial lipodystrophies with insulin resistance. The prevalence is unknown. Clinically, it is mainly characterized by the loss of subcutaneous adipose tissue in the lower parts of the body (limbs, buttocks, trunk) accompanied by an accumulation of adipose tissue in the face and neck, resulting in pseudo-cushingoid facies. Other clinical signs include acanthosis nigricans (a skin lesion associated with insulin resistance), muscle hypertrophy with prominent veins in the limbs, and hepatomegaly with liver steatosis. Symptoms develop progressively during adolescence. In females, hirsutism often sets in after puberty along with irregular menses due to a polycystic ovary syndrome. Biological findings include hypertriglyceridemia that may be major and cause acute pancreatitis, low HDL-cholesterol, and hyperinsulinemia related to insulin resistance. Diabetes frequently occurs over the course of the disease. The risk of cardiovascular problems is very high. The syndrome is transmitted in an autosomal dominant manner. The causal gene for Dunnigan syndrome, located on 1q21, codes for lamin A/C. Most cases are due to a heterozygous substitution at codon 482 (C-terminal domain). Other alterations in this gene are responsible for cardiac and/or skeletal muscular dystrophies, a form of Charcot-Marie-Tooth axonal neuropathy, premature ageing syndromes (acromandibular dysplasia, Hutchinson-Gilford progeria), and restrictive dermopathy. Treatment consists of correcting metabolic abnormalities with diets and/or drugs (hypolipidemics and antidiabetics). Due to the fact that mixed phenotypes have been described, cardiac examinations have to be performed in patients with Dunnigan syndrome to eliminate life-threatening conduction defects.
Last update: February 2005