Familial chylomicronemia syndrome. A sixty year follow-up in two siblings and their kindreds. Nosological and clinical considerations.

Familial chylomicronemia syndrome (FCS) is a rare and severe genetic disorder, characterized by marked elevation of plasma triglycerides, often diagnosed in infancy. We describe the long-term follow-up (almost 60 years), the diagnostic assessment and the management of two siblings with severe hypertriglyceridemia and a history of pancreatitis who also developed cardiovascular complications later in life. We recently disclosed that the surviving index case was homozygous for a pathogenic LPL gene variant (c.984 G>T, p.M328I). The same variant was also found in two apparently unrelated siblings with FCS living in the same geographical area as the index case.