Down's syndrome, also known as trisomy 21, is when someone is born with an extra chromosome. This usually happens by chance – so if it occurs in humans, does it occur in other animals too?
Do animals get Down's syndrome?
Human cells typically contain 23 pairs of chromosomes but people with Down’s syndrome have three, rather than two, copies of chromosome 21, resulting in a suite of developmental differences. Chromosome duplication syndromes occur in other animals too, though each is specific to the genetics of the species involved. However, there may be a direct link between Down’s and a syndrome in chimpanzees caused by an extra copy of chromosome 22. It has only been documented twice, but seems to involve eye and heart defects characteristic of Down’s syndrome.
Main image: chimpanzee in Kibale Forest, Uganda/Getty
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