
Defect that causes Huntington's disease has been corrected for the first time - tuxguy
http://www.bbc.com/news/health-42308341
======
TheBeardKing
Since this drug was developed on public funding in the UK, how does that
affect its pricing and incorporation in the NHS? I assume whoever gets the
license to sell it in the US will have exclusivity and make it expensive as
hell.

edit: Never mind, although the research took place at the University of
London, it was funded by Ionis Pharmaceuticals (US) and further by Roche
(Swiss multinational). The Guardian article relegates that bit of info to the
very last line, as if they were just a minor part of the effort.
[http://markets.businessinsider.com/news/stocks/Ionis-
Pharmac...](http://markets.businessinsider.com/news/stocks/Ionis-
Pharmaceuticals-Licenses-IONIS-HTT-Rx-to-Partner-Following-Successful-
Phase-1-2a-Study-in-Patients-with-Huntington-s-Disease-1010933822)

------
Merem
Great news. Although it's already too late for my mother, my sister can
definitely profit from it if it turns out well. And I guess I will have to
take the test now to see whether I have the disease as well...

~~~
filipncs
Best of luck.

------
dEnigma
Slightly off-topic, but there is an interesting connection between Chorea
Huntington and the evolution of complex brains and intelligence:

[https://www.economist.com/news/science-and-
technology/216457...](https://www.economist.com/news/science-and-
technology/21645713-could-key-evolution-human-brain-be-found-dreadful)

~~~
Real_S
Interesting connection with brain complexity, but note that the function of
the Huntinton's gene remains poorly understood.

Something that may be related... The same unstable repeat that causes the
disease is ancient and is conserved throughout mammals! So other mammals can
get a similar disease driven by the same mutations. This is useful for
generating models of the disease in other mammals (e.g. mice). Such
conservation of repeats is exceptionally rare.

------
ams6110
"Corrected" seems a bit strong. The treatment mitigates the cause of the
disease but it's not a cure, at least not yet. Does sound promising.

------
gradyj
This is awesome. Unfortunately, we lost both my cousin and uncle from this but
I'm glad I'm finally seeing a potential cure for this horrible disease.

------
lostlogin
If anyone has a bit of spare time, The Inheritance is a documentary worth
watching. It’s about a family with Huntington’s disease and them living and
dying with it. No affiliation.

[https://theinheritancedocumentary.com](https://theinheritancedocumentary.com)

------
canadiancreed
I wonder if this can be extended to other brain related illnesses such as
Alzheimers.

~~~
contravariant
I think the treatment will generalise better to other genetic diseases than to
other brain diseases, let alone a brain disease like Alzheimer for which the
cause is badly understood.

------
cromulent
Previous discussion:

[https://news.ycombinator.com/item?id=15896616](https://news.ycombinator.com/item?id=15896616)

------
agentofoblivion
Really cool to see progress on this terrible disease.

------
kurthr
TL;DR

Huntington's is caused by an error in a section of DNA called the huntingtin
gene. Normally this contains the instructions for making a protein, called
huntingtin, which is vital for brain development. But a genetic error corrupts
the protein and turns it into a killer of brain cells. The treatment is
designed to silence the gene.

One fear was the injections could have caused fatal meningitis. But the first
in-human trial showed the drug was safe, well tolerated by patients and
crucially reduced the levels of huntingtin in the brain.

The UCL scientist, who was not involved in the research, says the same
approach might be possible in other neurodegenerative diseases that feature
the build-up of toxic proteins in the brain. The protein synuclein is
implicated in Parkinson's while amyloid and tau seem to have a role in
dementias. Off the back of this research, trials are planned using gene-
silencing to lower the levels of tau.

~~~
thriftwy
I wonder how this genetic error could propagate wide enough for the disease to
get a name.

It's clearly maladaptive, isn't it?

Of course, same question could be asked for BRCA.

~~~
Real_S
There is something important about the type of mutations that drive
Huntington's.

Huntington's is caused by an expanded repeat composed of (CAG)n with n>40
repeats. Due to the instability of repeat regions, new mutations arise in this
gene at a relatively high rate. So, even if there were strong selection
against expanded repeats the disease would continue to exist. However, as
mentioned by others here, strong selection is unlikely due to the late age of
onset of the disease. So mutation continues to introduce the disease and
selection has been too weak to remove it.

In contrast, BRCA mutations differ from the Huntington mutations. BRCA
mutations are single "point" changes in the sequence, known as SNPs, that
disrupt the protein function. Novel point mutations are exceptionally rare.

So, unlike with BRCA, when investigating why Huntinton's disease exists, one
must consider BOTH mutation and selection.

~~~
fossuser
Huntington's also has an interesting place in the history of genetics, genetic
diseases, and heredity.

I wish I could find the excerpt, but the book The Gene talks about the
original research and it's an interesting story.

The book is worth reading in general (Siddhartha Mukherjee is a great writer
and it's really good).

[http://www.simonandschuster.com/books/The-Gene/Siddhartha-
Mu...](http://www.simonandschuster.com/books/The-Gene/Siddhartha-
Mukherjee/9781476733500)

------
jhiska
What the BBC doesn't say is that this is an important step towards eventually
being able to genetically modify healthy, adult people.

It's a trojan horse, and the clever thing about it is that there are valid
medical reasons for it.

~~~
Ovah
The described treatment degrades mRNA; no genetic modifications are made.

~~~
jhiska
I stand corrected.

I can't edit or remove my comment because Hacker News believes they know
better than me if I should have the ability to edit or remove my own comments.

