- Eligible Population Study participants must have participated in the preceding observation study (Prep-02: Appendix III) and be diagnosed with lipoprotein lipase deficiency, meeting the following criteria: (I) Their lipoprotein lipase activity levels in post-heparin plasma should be ≤20 % of normal; (II) Confirmed homozygocity or compound heterozygocity for mutations in the LPL gene; (III) Post-heparin plasma LPL mass should be >5% of normal; (IV) Median fasting plasma TG concentrations >10.00mmol/L, as determined on the basis of 5 consecutive time points in the preceding observation study with a history of pancreatitis.