A Case Report of Familial Chylomicronemia Syndrome With Infantile Onset: One-Year Follow-Up on Lipid Profile and Growth Development.

Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disease caused by a biallelic loss-of-function mutation in the lipoprotein lipase (LPL) gene or its cofactors. This case report describes the diagnosis, management, and one-year follow-up of an infant with FCS. The patient presented in early infancy with severe hypertriglyceridemia. Diagnosis was confirmed by genetic testing, which revealed a compound heterozygous mutation in the LPL gene. Management centered on a strict low-fat diet with medium-chain triglyceride (MCT) supplementation. Over a one-year follow-up period, significant improvements in triglyceride levels and catch-up growth were observed, highlighting the critical importance of early diagnosis and dietary intervention.