Familial partial lipodystrophy (FPLD) is divided into six subtypes of the disease. It is not known yet which gene is mutated to cause FPLD type 1. Type 2 is caused by mutations in lamin A, which can be either through LMNA mutations or ZMPSTE24 mutations. Type 3 has been shown to be linked to PPARG mutations. The LIPE gene causes triacylglycerol breakdown. Mutations in this gene lead more breakdown and causes type 6 FPLD. CIDEC inhibits LIPE. Mutations in CIDEC lead to type 5 FPLD. PLIN1 stimulates CIDEC and mutations in this leads to type 4 FPLD.
The phenotype related to all types of FPLD, is a loss of adipose tissue in the limbs and some metabolic abnormalities. With FPLD type 1 there is a loss of subcutaneous fat from the limbs. Patients with type 2 have an increased muscularity and a loss of fat in the limbs. There is also an accumulation of fat in the face and neck. In type 3 there is a loss of adipose tissue in the distal part of the limbs. Type 4 patients have shown to have small adipocytes, macrophage infiltration and fibrosis of adipose tissue. In type 5, there are small compartments in lipid droplets. Lastly, type 6 FPLD shows an increased visceral fat, hepatosteatosis, insulin resistance, and diabetes. Some patients may show muscular dystrophy and elevated serum creatine phosphokinase