APOC2 and familial chylomicronemia syndrome: (B) Familial chylomicronemia syndrome (FCS) is a syndrome characterized by high levels of chylomicrons due to autosomal recessive mutation of the lipoprotein lipase (LPL) gene located on chromosome 8p21.3 or the Apolipoprotein C2 (APOC2) gene located on chromosome 19q13.32.