Familial chylomicronemia syndrome (FCS) is a genetic entity with autosomal recessive inheritance. Mutations in genes (such as APOC2, APOAV, LMF-1, GPIHBP-1) that code for proteins that regulate the maturation, transport, or polymerization of lipoprotein lipase-1 are the most common causes, but not the only ones. The objective of this study was to report the first documented case in Ecuador. CLINICAL CASE: A 38-year-old man presented with chronic hepatosplenomegaly, thrombocytopenia, pancreatic atrophy, and severe hypertriglyceridemia refractory to treatment. A molecular analysis was performed by next generation sequencing that determined a deficiency of Lipoprotein Lipase OMIM #238600 in homozygosis. Genetic confirmation is necessary in order to establish the etiology of HTGS for an adequate management of this pathology.

Hypertriglyceridemia is common in children with systemic lupus erythematosus (SLE). A retrospective analysis of the baseline clinical-pathological presentation and treatment outcome (status of lipid profiles) was performed in two children with SLE, who presented with extreme hypertriglyceridemia over a follow-up period of four weeks. The children were treated with prednisolone, mycophenolate mofetil (MMF), hydroxychloroquine and hypolipidemic agents, depending on their disease status. On serial follow-up, the first child showed a significantly raised serum triglyceride level after receiving one week of oral prednisolone therapy. Anti-lipoprotein-lipase (LPL) autoantibody was absent. Lipid profile levels of this child gradually improved after replacing oral prednisolone with another immunosuppressant, namely MMF. The second child presented with extreme hypertriglyceridemia with positive anti-LPL autoantibody. She responded to plasmapheresis followed by increasing the dose of immunosuppressant. So, extreme hypertriglyceridemia in children with SLE may be steroid induced or due to presence of anti-LPL auto antibody. Management should be individualized depending on the etiology.

The majority of severe primary hypertriglyceridemia (HTG) are diagnosed in adults, and their molecular bases have not yet been fully defined. The promoter, coding regions and intron-exon boundaries of LMF1 were sequenced in 112 patients with severe primary hipertrigliceridemia (defined as TG above 500mg/dl). Five patients (4.46%) were carriers of four rare variants in the LMF1 gene associated with HTG, which participate in lipoprotein lipase (LpL) function. Also, we have identified two common variants, c.194-28 T>G and c.729+18C>G that were associated with HTG, with a different allelic frequency to that observed in the general population. A bioinformatic analysis of all found variants was conducted, defining the following as potentially harmful: p.Arg364Gln, p.Arg451Trp, p.Pro562Arg and p.Leu85Leu. Our results suggest that LMF1 mutations are involved in a substantial proportion of cases with severe HTG, putting together the moderate-aggressive effect of rare mutations with polymorphisms classically associated with this disease.