We investigated a girl with severe hypobetalipoproteinemia and lipid malabsorption.
Abetalipoproteinemia and chylomicron retention disease were excluded.
She was found to be homozygous for Arg505Trp substitution in apolipoprotein B.
This missense mutation is located in the βα1 domain of apolipoprotein B.
The mutation reduced the secretion of human apoB-48 in McA-RH7777 cells.