Just as an aside from hepatic lipids. This study is about heart disease within a group of people with heterozygous FH. The full text doesn't say much more than the abstract. Here are the two punch lines:
"The combination of DM [diabetes mellitus] or IGT [impaired glucose tolerance] with FH was associated with a further increase in the prevalence of CAD"
"total cholesterol levels were not significantly different [ie between normal, IGT or DM affected people with FH]"
The basic conclusion I get from the study is that if you take a group of statin naive FH "victims", it's not the variation of LDL cholesterol level in their bloodstream which determines CV disease, it's the degree of glucose dysregulation which seems to matter within the group.
Now what I want to know is if a heterozygous FH person maintained chronic and rigid normoglycaemic, 24/7 and so kept their blood glucose always below, say 5.0mmol/l, would they have ANY CVD above that of a non FH person under the same circumstances. Especially if they were omega 6 fatty acid restricted....
Mutations of the gene for the LDL receptor seem to be common and to come in an enormous number of flavours. If it was so very important to have two fully functional copies of the gene I would expect it to be much more highly conserved.