Chylomicronemia: Differences between familial chylomicronemia syndrome and multifactorial chylomicronemia. 
Chylomicronemia can be either monogenic or multifactorial.  The monogenic form, namely familial chylomicronemia syndrome (FCS), is a rare autosomal recessive disease that strongly predisposes to pancreatitis.  However, the clinical variables differentiating FCS from multifactorial chylomicronemia (MCM) are not well established.  The aims of the present study were to describe a well-defined cohort of FCS subjects and to investigate the differences between patients with FCS and MCM.  A total of 25 FCS and 36 MCM patients were included in the present study.  FCS patients were genetically confirmed, whereas MCM patients had negative genetic testing, triglycerides above 10 mmol/L at least once and the presence of both chylomicrons and VLDL in plasma.  FCS patients presented a significant higher frequency of pancreatitis (60% vs. 6%), multiple pancreatitis (48% vs. 3%) and abdominal pain (63% vs. 19%) and a lower frequency of metabolic abnormalities than in the MCM group (p < 0.0001).  In addition, the frequency of cardiovascular events was higher in the MCM group than in the FCS group (17% vs. 0%), although the difference was not statistically significant (p = 0.07).  In a univariate regression model, the significant predictors of FCS were age at first manifestation (β = -2.11, p = 0.0005), body mass index (BMI) (β = -1.82, p < 0.001) and gamma-glutamyl transferase (GGT) (β = -1.64, p = 0.001).  Our study identified several variables that significantly differentiates FCS from MCM patients.  These results need to be replicated in larger cohorts to identify the independent predictors of FCS.