Colleen was tiny. And not in the petite, slim sort of way - she was literally tiny, a scant 4 ½ inches tall. She hadn't always been tiny. A mere month ago, sh had stood an average 5 foot 5. Lurking in her DNA, however, had been a quirky little gene, dormant for the first 21 years of her life. The day after her 21st birthday, she'd stared at herself in the mirror, wondering if her height had changed.After 5 days, it was obvious that something was going on, so it was off to the doctor, who