It took 18 years for Patricia Weltin to get the correct diagnosis. Her daughters have Ehlers-Danlos syndrome, a connective tissue disorder involving too-loose joints that easily dislocate as well asoverly elastic, fragile skin and many complications. That long road to the right diagnosis is known as the “diagnostic Odyssey,” says Dr. Christopher Austin, director of the National Center for Advancing Translational Sciences, part of the National Institutes of Health. With rare diseases, he says, most doctors have never seen a case, so “patients go from doctor to doctor to doctor.” Now, he says, with the ease of worldwide communication, the journey to diagnosis takes an average two-and-a-half to three years. Read on for more rare disorders.