In 1950, when Marybeth Solinski was born, a diagnosis of Down syndrome was practically a death sentence.
Children with the condition often died before their 10th birthday.
Yet Solinski, at 59, has outlived her parents. She has even joined AARP.
Her longevity illustrates the dramatic progress for people with Down syndrome. Thanks to better medical care, the average life expectancy for a child with Down syndrome is now 60 years, according to the National Down Syndrome Society, which estimates that about 400,000 people are living with the condition in the USA.
As they live onger, adults with Down syndrome - who have an extra copy of chromosome 21 - are teaching scientists about the genetic roots of aging, says Ira Lott, head of pediatric neurology at the University of California - Irvine School of Medicine.
Scientists today are searching this chromosome, which contains only about 200 of the body's roughly 200,000 genes, to learn why people with Down syndrome suffer disproportionately from some health problems, such as Alzheimer's disease,