Endocrine Abstracts

JOINT3455

Background: Lipoprotein lipase (LPL) deficiency is a rare genetic disorder of lipid metabolism. The LPL enzyme induces the hydrolysis of triglycerides from lipoproteins to generate free fatty acids. LPL deficiency results in severe hypertriglyceridemia and chylomicronaemia and is associated with recurrent pancreatitis ^(1).

Case Presentation: We report the case of a previously well male infant, who presented at 6 months of age with fever, vomiting and dehydration. He was admitted for intravenous rehydration. His CRP and urea were unanalysable as the blood sample was lipaemic. Subsequent testing revealed a cholesterol of 9.26mmol/l (3.0-5.0) and triglycerides of 34.6 mmol/l (0.4-2.0). His family history was significant for a paternal history of hypercholesterolaemia and fatty liver disease. Both of his parents are members of the Irish travelling community and are third cousins. Repeat bloods tests two days later showed a downtrending cholesterol (3mmol/l) and triglycerides (4.5mmol/l). His HDL cholesterol was low 0.46mmol/l (1.0-2.0) and he had normal liver function. He clinically improved and was discharged home with planned outpatient follow-up. He was readmitted 2 weeks later with poor feeding and a tender abdomen. His bloods were lipaemic with a raised lipase 181IU/L (13-60), raised triglycerides 22.6mmol/l and raised cholesterol 6.3mmol/l. His amylase and liver function tests were within normal limits. Following this he was diagnosed with acute pancreatitis and suspected familial chylomicronaemia syndrome, most commonly associated with LPL deficiency. This male infant was transitioned to Monogen, a formula low in long-chain triglycerides and solid fat intake was restricted with supplementation of fat soluble vitamins. His target triglyceride level is <10mmol/l. His triglycerides (2.6mmol/l) and cholesterol (3.7mmol/l) levels have remained low on this diet and at 2 years old he is growing well along the 75^thto 91st centile for height and weight.

Results: Genetic testing revealed that he was Heterozygous for the variant c.897_1018+1939dup p.? in the lipoprotein lipase gene. Parental samples have been sent and are pending.

Discussion: Familial LPL deficiency is a rare disorder. We report the only case in the Republic of Ireland associated with this mutation. This genetic variant has been detected in five individuals in the Amsterdam UMC laboratory, only two of these, like our case, had hypertriglyceridaemia. Restriction of dietary fat is usually sufficient to reduce chylomicronaemia and hypertriglyceridaemia. Drugs that lower lipids levels in the body are ineffective in these cases.Reference1. Balasubramanian, S. (2024) Lipoprotein lipase deficiency, StatPearls [Internet]. Available at: https://www.ncbi.nlm.nih.gov/books/NBK560795/