Novel Mutation (c.G1124A) in Exon 9 of the APOB Gene Causes Aberrant Splicing and Familial Hypobetalipoproteinemia

[摘要] Familial hypobetalipoproteinemia (FHBL) is commonly caused by mutations in the apolipoprotein B gene ( APOB ). The APOB gene encodes 2 proteins, apolipoprotein (apo) B-48 and apo B-100. Apo B-48 is formed in the intestine and is essential for the formation and recognition of dietary derived chylomicrons, and apo B-100 is found in VLDLs and LDLs of hepatic origin and is involved in the endogenous transport of triglycerides, cholesterol, and fat-soluble vitamins. A number of abnormally truncated apo B proteins have been described, and by convention are referred to by a centile system reflecting their apparent M r in relation to apo B-100 (1).Truncations shorter than apo B-27 are not expressed in lipoproteins, and those shorter than apo B-75 are underrepresented in LDL (2)(3)(4). Consequently homozygous mutations in the N-terminal third of APOB result in the virtual absence of both apo B-48 and apo B-100 and their corresponding lipoproteins, and thus very low concentrations of plasma triglycerides, cholesterol, and the fat-soluble vitamins. This condition …

[学科分类] 过敏症与临床免疫学