Identification of compound heterozygous mutations (G188E/W382X) of lipoprotein lipase gene in a Japanese infant with hyperchylomicronemia: the G188E mutation was newly identified in Japanese.

We herein report a case of a 5-month-old Japanese female (patient AN) with fasting hyperchylomicronemia due to a primary lipoprotein lipase (LPL) deficiency. Patient AN was compound heterozygous for a missense mutation (GG818G-->GAG/Gly188-->Glu; G188E) in exon 5 and a nonsense mutation (TGG1401-->TGA/Trp382-->Stop; W382X) in exon 8 of the LPL gene. This resulted in less than 10% of the control levels for both the LPL activity and immunoreactive LPL mass in the postheparin plasma. A G188E mutation was thus identified for the first time in a Japanese, and the haplotype of this G188E allele was different from that of the G188E alleles identified in other ethnic groups. This additional mutation might be useful for early diagnosis of LPL gene aberrations in Japanese patients with fasting hyperchylomicronemia.