On the other hand, multifactorial chylomicronemia syndrome (MCS) is a polygenic disorder and the most frequent cause of CS that results from the presence of multiple genetic variants that include both rare heterozygous variants in the LPL, APOC2, APOA5, apolipoprotein B (APOB), glucokinase regulatory protein (GCKR), LMF1, GPIHBP1, and cyclic AMP-responsive element-binding protein 3-like protein 3 (CREB3L3) genes and more frequent variants with small effects in ~40 genes [15]. Here, CREB3L3 is linked to Cowden syndrome 1.