Bella, the youngest of Santorum's seven children, suffers from a rare chromosomal disorder called Trisomy 18, which causes severe medical and developmental problems.

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Her 18-year-old son Jermarl Henderson, who has a chromosomal disorder called DiGeorge Syndrome, has had multiple open-heart surgeries and requires intensive, complex therapy, she said.

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English Heritage said results of recent analysis of Peter's portrait by a professor of genetics, now suggested he had Pitt-Hopkins syndrome, a chromosomal disorder first identified in 1978.

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Rick Santorum ended his presidential bid in the face of long odds, slowing fundraising and another bout of illness for his youngest child, who has a chromosomal disorder.

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Sitting in the hospital with his daughter, who was born with a potentially fatal chromosomal disorder, for the second time during this campaign put that in perspective for Santorum, especially since the delegate math was not on his side, the source said.

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