A century after Down syndrome was first described, scientists discovered that the root cause of this disorder is a condition called trisomy 21. What strides in research have been made since then?

There is also an apparent "bump" in trisomy among teenage girls. This slight increase has also been observed in several studies of Down syndrome, and might reflect a tendency to non-disjoin in the ...

Among 19 autopsied cases of 17–18 trisomy syndrome, 10 confirmed by cytogenetic studies, nine diagnosed on the basis of phenotypic characteristics, seven cases of neonatal hepatitis were found ...