Alzheimer's disease passed down to children

According to a new study, Alzheimer's disease may be passed from parents to children in some people scientists said after finding carriers of a faulty gene are two to three times more likely to have memory problems. Researchers found people who had the faulty gene and whose parents had either dementia or Alzheimer’s disease were more likely to have problems with memory even though their average age was only 59. The effect was the equivalent of having a brain that was 15 years older, the researchers said. 
I find this extremely interesting, not just because my dad had AD (and I'm terrified of getting it), but because of how young he was when he was diagnosed.  His father died very young so I have no idea if he would have gotten AD, and his mother had all sorts of mental problems, dying when she was in her early 60's (I think; I never met her even though she lived only 1 town over my whole life).   My dad's diagnosis came when he was 62 and in hindsight he had symptoms in his late 50's if not earlier.

The findings showed that people whose parents suffered from the condition were significantly more likely to do badly on visual and verbal memory tests than those with healthy parents but only if they carried the faulty gene, called ApoE4. ...It is thought around one in seven people carry the ApoE4 gene and this causes their bodies to produce a lipoprotein, which is a combination of fat and protein, which sticks on to parts of brain cells. Once that lipoprotein is stuck on the cell it allows other chemicals to stick on and the whole lot can be absorbed by the brain cell where a process begins that can cause damage in the long-term.

There's a test for it, but having the gene doesn't guarantee that you'll get AD, and not having the gene doesn't guarantee you won't. So I guess that right now it's interesting information, but not particularly useful.
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