00:01
So mutation in the htt gene caused huntington disease.
00:05
The hontenden gene provide instruction for making a protein called huntington.
00:09
Now, it looks like the, you know, the huntington protein appeared to have a very important role in neurons.
00:18
So the mutation of httt causes huntington disease, involve a dna segment that's not as a c .a .g trinucleotide repeat.
00:25
So in normal people, the cag repeat between 10 to 35 times.
00:34
However, in huntington disease people, this repeat increased to 36 to 120 copies.
00:47
Now, usually between 36 to 39 copies of the cag, people may or may not develop the disease.
00:54
However, when people have more than 40 copies, it definitely most likely develop this disorder.
01:00
So first of all, what amino acid is encoded by cag, and why would the extra repeat be a problem? so first of all, cag encode for a particular amino acid glutamine.
01:15
And the single letter symbol for glutamine is q.
01:19
So a lot of time, the huntington disease is also called the polyglutamine disease or polyqude disease.
01:36
So how does this extra polyglutamine chain cause issue? so this is the regular, say, huntington protein...