Chylomicron

In the small intestine, dietary triglycerides are emulsified by bile and digested by pancreatic lipases, resulting in the formation of monoglycerides and fatty acids.

Mature chylomicrons are released through the basolateral membrane of enterocytes (via the secretory pathway) into lacteals,[7] lymphatic capillaries in the villi of the small intestine.

Clinical manifestations of this disorder include eruptive xanthomas, lipaemia retinalis, hepatosplenomegaly, recurrent abdominal pain, and acute pancreatitis.

[10] Abetalipoproteinemia (ABL; OMIM 200100) is a rare autosomal recessive disorder caused by mutations in both alleles of the MTP gene.

[11] Homozygous hypobetalipoproteinemia (Ho-HBL; OMIM 107730) is an extremely rare inherited disorder characterized by improper packaging and secretion of apoB-containing lipoproteins due to mutations in both alleles of the APOB gene.

Clinical manifestations vary, ranging from lack of symptoms to features overlapping with those of ABL, including fat malabsorption and vitamin deficiencies.

[11] Chylomicron retention disease (CMRD; OMIM #607689) is a rare autosomal recessive disorder caused by mutations in the SAR1B gene.

Patients with CMRD present with chronic diarrhea, failure to thrive, hypocholesterolemia, and low levels of fat-soluble vitamins.

The enterocytes of these patients fail to secrete chylomicrons into the lymph, leading to lipid accumulation and characteristic mucosal changes in the small intestine.

[11] Familial chylomicronemia syndrome (FCS), also known as Type I hyperlipoproteinemia, is characterized by massive hypertriglyceridemia, abdominal pain, pancreatitis, eruptive xanthomas, and hepatosplenomegaly.

This condition is caused by mutations in genes such as LPL, APOC-II, APOA-V, LMF1, and GPIHBP1, which are involved in the regulation of triglyceride-rich lipoprotein catabolism.