【探索世界】基因外遺傳現(xiàn)象(5/30)
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Henry Angelman
pediatrician
syndrome
incapacitated
key sequence of DNA
Chromosome 15
paradox
Prader-Willi syndrome
Named after Henry Angelman, the pediatrician who first described Angelman syndrome. He referred to them as happy puppet children because it described, to some extent, the features. They have a rather jerky sort of movement when they are walking. These children have no speech. They are severely incapacitated in terms of learning, but are uncharacteristically happy as they are smiling all the time.
The condition was caused by a genetic fault: a key sequence of DNA was missing, deleted from Chromosome 15.
Then we came across a paradox: at the same time, er, the same change, the same little deletion of Chromosome 15 had been clearly associated with a quite different syndrome, much milder in terms of, er, of intellectual impairment, the Prader-Willi syndrome. These children are characterized by being very floppy at birth, but once they started eating properly and so on, they then had an insatiable appetite and would get very, very large.
What Pembrey saw simply made no sense. Here were two completely different diseases, Angelman syndrome and Prader-Willi syndrome being caused by exactly the same genetic fault.
- 相關(guān)熱點:
- 現(xiàn)在完成時習(xí)題