Triple X syndrome is also called trisomy X, triplo X syndrome and XXX syndrome.

CNN: Triple X syndrome

He and his wife of 22 years, Claudia, have no children, and the cause became important to them after their niece was born with trisomy 13, a syndrome caused by an extra 13th chromosome.

FORBES: The New Barbarians

In her lab, Dr. Cherry said she had found four out of six positive results for Trisomy 18, or Edwards syndrome, which the tests also detect, appeared to be false alarms after follow-up testing.

WSJ: New Questions on Cutting-Edge Prenatal Tests