Two novel mutations of the LPL gene in two Chinese family cases with familial chylomicronemia syndrome.

The aim of this study was to investigate the clinical features and genetic causes of two family cases with familial chylomicronemia syndrome (FCS). Clinical manifestations of proband 1 and her families, and also proband 2 showed severe hypertriglyceridemia, especially the triglycerides levels of two probands were extremely high. Gene sequencing results showed that the LPL genes in each of the two probands had a new mutation site. For the proband 1, a compound heterozygous mutation at c.429 (c.429 + 1G > T) was detected in the LPL gene, which was splicing mutation and inherited from her mother. Homozygous mutation was detected in the LPL gene of proband 2, the nucleotide mutation at c.802 (c.802C > T) exhibited missense mutation, his parents and brother had a heterozygous mutation at the same site. It was confirmed that the conservative lipoprotein lipase superfamily domain changed an amino acid from histidine to tyrosine at p. 268 (p. His268Tyr). Flow cytometry confirmed the deficient expression of LPL protein in two families. These results indicated that the mutation in LPL gene might be the cause of familial chylomicronemia syndrome.