Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about Huntington's disease.

And you can find written notes on this topic at zero tofinals.com slash Huntington's

or in the neurology section of the second edition of the zero to finals medicine

book and you can find flashcards and questions to train your knowledge on this content and

help you remember the information for longer at members.0.0.com so let's get straight into it. Huntington's disease, also called

Huntington's Korea, is an autosomal dominant genetic condition that causes progressive

neurological dysfunction. It's a trinucleotide repeat disorder, which involves a genetic mutation in the

HTT gene on chromosome 4, which codes for the Huntington or HTT protein. Symptoms of Huntington's

disease typically begin aged 30 to 50.

Let's talk about trinucleotide repeat disorders.

Nucleotides are the building blocks of DNA, and they include aden, cytosine, guanine, and thymine.

Trinucleotide repeats refer to repetitions of a sequence of three nucleotides, for example,

C-A-G, C-A-G, C-A-G, C-A-G, C-A-G, C-A-G.

Other examples of trinucleotide repeat disorders include fragile X-Syndrome, Spino Cerebella ataxia,

myotonic dystrophy and frederic ataxia.

Let's talk about anticipation.

Huntington's career displays a feature called genetic anticipation.

Anticipation occurs with trinucleotide repeat disorders, where successive generations of affected

individuals have more repeats in the gene, and this results in an earlier age of onset and an

increased severity of disease. A tom tip for you, anticipation is a common concept tested in

exams and it's worth remembering with Huntington's disease. Let's talk about the presentation.

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