Current Diagnosis and Management of Familial Hypobetalipoproteinemia 1

J Atheroscler Thromb. 2024 May 3. doi: 10.5551/jat.RV22018. Online ahead of print.ABSTRACTFamilial hypobetalipoproteinemia (FHBL) 1 is a rare genetic disorder with an autosomal codominant mode of inheritance and is caused by defects in the apolipoprotein (apo) B (APOB) gene that disable lipoprotein formation. ApoB proteins are required for the formation of very low-density lipoproteins (VLDLs), chylomicrons, and their metabolites. VLDLs transport cholesterol and triglycerides from the liver to the peripheral tissues, whereas chylomicrons transport absorbed lipids and fat-soluble vitamins from the intestine. Homozygous or compound heterozygotes of FHBL1 (HoFHBL1) are extremely rare, and defects in APOB impair VLDL and chylomicron secretion, which result in marked hypolipidemia with malabsorption of fat and fat-soluble vitamins, leading to various complications such as growth disorders, acanthocytosis, retinitis pigmentosa, and neuropathy. Heterozygotes of FHBL1 are relatively common and are generally asymptomatic, except for moderate hypolipidemia and possible hepatic steatosis. If left untreated, HoFHBL1 can cause severe complications and disabilities that are pathologically and phenotypically similar to abetalipoproteinemia (ABL) (an autosomal recessive disorder) caused by mutations in the microsomal triglyceride transfer protein (MTTP) gene. Although HoFHBL1 and ABL cannot be distinguished from the clinical manifestations and laboratory findings of the proband, moderate hyp...

Source: Journal of Atherosclerosis and Thrombosis - May 6, 2024 Category: Cardiology Authors: Tetsuji Wakabayashi Manabu Takahashi Hiroaki Okazaki Sachiko Okazaki Koutaro Yokote Hayato Tada Masatsune Ogura Yasushi Ishigaki Shizuya Yamashita Mariko Harada-Shiba Committee on Primary Dyslipidemia under the Research Program on Rare and Intractable Dis Source Type: research