A three month-old infant with severe hyperchylomicronemia: molecular diagnosis and extracorporeal treatment.

Objective: Chylomicronemia syndrome presenting in childhood is a rare recessive disorder due to mutations of lipoprotein lipase (LPL) and more rarely of APOC2, APOA5, GPIHBP1 or LMF1 genes. It often requires urgent and suitable treatment to avoid acute pancreatitis. The aim of this study was the molecular characterization and treatment of a 3 month-old infant with plasma triglycerides (TG) > 300 mmol/L.

Methods: All candidate genes were sequenced. The patient was submitted to one plasma-exchange (PEX) procedure and subsequently to a rigid lipid-lowering diet (milk: Monogen(®)).

Results: The proband was homozygous for a novel LPL mutation (c.242G > A, p.G81D) which in silico results pathogenic. After PEX, which was well tolerated, TG dropped to 64 mmol/L. During 5-month follow-up there was a clear trend towards lower and stable TG values.

Conclusion: PEX is applicable in subjects with very low body weight when the extreme severity of the clinical picture has no therapeutic alternatives.