ABSTRACT
Abstract Familial chylomicronemia syndrome (FCS) is an autosomal recessive disorder, characterized by alterations in the catabolism of chylomicrons and by increased levels of plasma triglycerides. It has been shown that about 60-90% of FCS patients have biallelic mutations in the LPL gene and the remaining patients have mutations in genes encoding proteins closely related to LPL function. The objective of this manuscript is to illustrate the different clinical scenarios of FCS presentation, and to guide practitioners on the usefulness of genetic tests in each of them. To this end, several published papers about recommendations for the diagnosis of FCS are discussed briefly, in addition to the presentation of several hypothetical cases, highlighting different clinical presentations and possible associated genetic findings. These cases illustrate the multiplicity of potential aspects of family history, clinical manifestations, biochemical parameters, and patterns of genetic variants found in genomic analyses of FCS.