Involvement of a homozygous exon 6 deletion of LMF1 gene in intermittent severe hypertriglyceridemia.

Severe hypertriglyceridemia (HTG), characterized by triglycerides (TG) permanently over 10 mmol/L, may correspond to familial chylomicronemia syndrome (FCS), a rare disorder. However, hypertriglyceridemic patients more often present multifactorial chylomicronemia syndrome (MCS), characterized by highly variable TG. A few nonsense variants of LMF1 gene were reported in literature in FCS patients. In this study, we described a woman with an intermittent severe HTG. NGS analysis and the sequencing of a long range PCR product revealed a homozygous deletion of 6507 base pairs in LMF1 gene, c.730-1528_898-3417del, removing exon 6, predicted to create an in-frame deletion of 56 amino acids, p.(Thr244_Gln299del). Despite an exon 6 homozygous deletion of LMF1 , the patient's highly variable lipid phenotype was suggestive of MCS diagnosis. • Deleterious variations in the LMF1 gene leading to hyperchylomicronemia are rare. • No copy number variation was previously reported in the LMF1 gene. • The study describes the first deletion in the LMF1 gene, removing exon 6. • This deletion is associated with a multifactorial chylomicronemia syndrome phenotype. [ABSTRACT FROM AUTHOR]