Apolipoprotein B gene mutations and fatty liver in Japanese hypobetalipoproteinemia.

Abstract

BACKGROUND:

Familial hypobetalipoproteinemia (FHBL) is a hereditary disorder characterized by decreased plasma concentrations of low-density lipoprotein cholesterol. The best-characterized causes of FHBL are apolipoprotein B (apoB) gene mutations, which produce truncated apoB proteins. Fatty liver is thought to be frequent in FHBL, owing to impaired secretion of very-low-density lipoprotein from the liver. Homozygotes for FHBL present with extremely low concentrations of plasma lipids, and may suffer from deficiencies of fat-soluble vitamins. The objectives of this study were to identify apoB-defective FHBL subjects and investigate fatty liver in Japanese population.

METHODS:

We screened 14 hypocholesterolemic subjects for apoB gene mutations by PCR-SSCP and performed liver ultrasonography in a Japanese population.

RESULTS:

We identified an apoB-82 homozygote in one subject and an apoB-13.7 heterozygote in another subject. Four of 6 individuals with FHBL presented with fatty liver in those 2 FHBL families. Liver biopsy of the apoB-13.7 heterozygote, which had obesity and insulin resistance, showed severe fatty liver. The apoB-82 homozygote was asymptomatic with fat-soluble vitamin concentrations being normal, possibly due to spared secretion of apoB-48 from the intestine and increased plasma concentrations of high-density lipoprotein cholesterol.

CONCLUSION:

ApoB gene mutations might not be rare and that fatty liver might be frequent in Japanese FHBL.

• Authors: Shoji Katsuda, Masa-Aki Kawashiri, Akihiro Inazu, Hayato Tada, Masayuki Tsuchida, Yoshibumi Kaneko, Tsuyoshi Nozue, Atsushi Nohara, Toshihide Okada, Junji Kobayashi, Ichiro Michishita, Hiroshi Mabuchi, Masakazu Yamagishi
• Journal: Clinica chimica acta; international journal of clinical chemistry (Clin Chim Acta) Vol. 399 Issue 1-2 Pg. 64-8 (Jan 2009) ISSN: 1873-3492 [Electronic] Netherlands
• PMID: 18848826 (Publication Type: Case Reports, Journal Article)

Chemical References

• Apolipoproteins B
• Cholesterol, LDL

Topics

• Adult
• Aged
• Apolipoproteins B (genetics, metabolism)
• Asian People (genetics)
• Base Sequence
• Cholesterol, LDL (genetics, metabolism)
• Fatty Liver (diagnostic imaging, genetics, metabolism, pathology)
• Female
• Genotype
• Humans
• Hypobetalipoproteinemias (diagnostic imaging, genetics, metabolism, pathology)
• Insulin Resistance (genetics)
• Male
• Middle Aged
• Mutation (genetics)
• Obesity (genetics)
• Ultrasonography