Dyslipidaemia in a boy with recurrent abdominal pain, hypersalivation and decreased lipoprotein lipase activity

An 8-year-old boy with frequently recurring pancreatitis-like abdominal pain, Fredrickson type V dyslipidaemia, and significantly decreased post-heparin plasma lipoprotein lipase (LPL) activity is described. In order to exclude familial LPL deficiency, the complete LPL coding gene sequence was analysed revealing compound heterozygosity for two mutations (Asp⁹Asn, Ser⁴⁴⁷Ter) which are not supposed to considerably impair lipolytic enzyme activity. However, until now the combination of both these mutations in one patient has not been observed. In addition to the common symptoms of LPL deficiency, a striking feature of unknown origin was hypersalivation. Treatment including a fat-restricted diet, omega-3 fatty acids, and nicotinic acid led to long symptom-free intervals. Symptoms recurred however when the diet was not strictly adhered to. Conclusion. LPL deficiency is a rare cause of abdominal pain in childhood and deserves careful treatment in order to avoid pancreatitis. The presented patient is a unique compound heterozygote for two mutations which do not abolish lipolytic activity in the homozygote state. Identification of other individuals with this genotype is necessary to understand the phenotype in our patient.