I’m busy preparing my lecture for genetics this morning, in which I’m going to be talking about some chromosomal disorders … and I noticed that this summary of Fragile-X syndrome that was on the old site hadn’t made it over here yet. A lot of the science stuff here actually gets used in my lectures, so they represent a kind of scattered online notes, so I figured I’d better put this one where I can find it.
I haven’t even finished grading the last of the developmental biology papers, and already my brain is swiveling towards the genetics literature, as I get in the right frame of mind to teach our core genetics course in the spring. And, lo, here is a new paper in PNAS that addresses details of a topic I bring up every time.
There are a surprising number of heritable diseases that share a couple of common traits: they are neurodegenerative, causing progressive loss of neural control, and they also exhibit a phenomenon called genetic anticipation—they tend to get worse, with earlier onset and more severe affects with each generation. Some of these diseases may be rather obscure, for instance
Haw-River Syndrome (AKA Dentatorubral-pallidoluysian atrophy),
Friedreich Ataxia,
Machado-Joseph Disease, or
X-linked Spinal and Bulbar Atrophy Disease (AKA Kennedy Disease), but others you’ve probably heard of, like
Myotonic dystrophy and
Huntington Disease. These are dreadful diseases that are variable in their pattern of appearance, and have terrible symptoms, like loss of motor control, chorea, seizures, dementia, and eventually, death.