Meanwhile, more letters arrived. Christiano heard from a Texas pediatrician whose Pakistani-American family had sparse hair that broke easily and sometimes coiled beneath the skin because it was too weak to penetrate the surface. By now she had set up a system: Find a mutant mouse with a similar phenotype and see if the human patient had a mutation on the equivalent gene. "This is our hat trick," she thought. But when she tested one candidate mouse with a known mutation, the trick failed.
Frustrated, Christiano turned to a colleague, who suggested she look at a lanceolate mouse, a rodent with sparse, stubbly hairs but no identified mutation. It took five years of gene hunting to find the source of the mouse's strange hair patterns. In 2002 a student in Christiano's lab was studying the Human Genome Project database and noticed an unnamed region where Christiano had predicted the human version of the lanceolate gene would reside. The gene proved to be severely mutated in both the Texas family and some lanceolate mice. "This one took a little bit longer," Christiano says, "but only because we had to wait for the genome project to catch up and point us in the right direction."
Unlike a disease such as hypertension, which follows a similar course in most sufferers, hair diseases come in many types. And while the most common disorders involve the absence of hair, some people grow too much. Christiano turned to a rare condition called hypertrichosis, whose sufferers are sometimes called wolf people. Instead of growing normal facial hair, they develop thick, pigmented scalp hair called terminal hair all over their faces. So unusual is their appearance that some people with hypertrichosis work as circus performers. The syndrome has different causes, but it can be inherited in families, and Christiano suspects it involves a single gene.
The problem of studying hypertrichosis is that so few people have the genetic form. So for the past six years, Christiano has been scouting research subjects all over the world. In 1998 she located two families in Europe. Then, in 2001, she flew to Monterrey, Mexico, where a colleague drove her to a rural open-air clinic. There she met a family with a quirky phenotype: those with excessive hair were also deaf and unable to speak. Many of them lived in shame, remaining inside and shaving constantly.
Meeting the family—especially an uncle and his young nephew—touched Christiano. "The uncle was just amazingly beautiful," she says. "I mean, I've never seen so much hair on one person. Others in the family were not as out about their disease, but he was very proud of his. He couldn't wait to take his shirt off and show me his chest.
"We could tell that the nephew looked up to this uncle as a guide to what his life was going to be like. In turn, the uncle looked at this kid as his responsibility. And they didn't even do sign language with each other. Even though they couldn't vocalize or hear each other, they had this bond that was just incredible."
Christiano took blood samples. She has not turned up any genetic clues yet, but if she succeeds, the impact could be staggering. Hypertrichosis is the mirror image of male-pattern baldness. With balding men, ordinary scalp hair is replaced by vellus, or peach fuzz. Among people with hypertrichosis, facial vellus is replaced by scalp hair. Unlocking the secret to hypertrichosis could lead to gene therapies not just for people with too much hair but also for some of those with too little.
Christiano is not a theorist. "Although she's a Ph.D.-trained scientist, she's always looking for the clinical relevance of her findings," says Hal Dietz, a researcher at the Institute for Genetic Medicine at Johns Hopkins University. "She's very emotionally attached to the patient populations. She's always looked for the relevance of her work to prenatal diagnosis of a condition, family counseling, and the development of new and rational treatment strategies."
Christiano's desire to connect with her research subjects was what brought her to Jerusalem last June. Hadassah University Medical Center claims the world's largest collection of patients with genetic hair diseases, including roughly half the documented cases of papular atrichia, the condition Christiano linked to the hairless gene. It also has many patients with alopecia, the disease that triggered Christiano's own hair loss and which remains unsolved. "It's extremely important not just to see the blood or the DNA but to see there are human beings behind this. And they suffer," says Hadassah dermatologist Abraham Zlotogorski, Christiano's principal Israeli collaborator. "It's very important for patients to see there's an international effort to find a cure for their problem." Conditions like papular atrichia are sometimes known as orphan diseases because they lack the frequency to merit much research. "But for patients, this is not an orphan disease," Zlotogorski says. "It's 100 percent of their problem."
When Christiano arrived at the clinic that Friday morning, the waiting room was already filling with the patients whose DNA she knew intimately. Several of the papular atrichia families had traveled from the West Bank and Jordan, braving bureaucracy and highway checkpoints solely for science's sake, as the disease still has no treatment. Emerging from the elevator, the geneticist saw two bald Palestinian girls, ages 3 and 8, who had come from the West Bank with their fathers, cousins in an intermarried family. Their heads were covered with kerchiefs. It was the first time Christiano had ever seen atrichia patients face-to-face. "Oh, my God," she whispered. "They're beautiful."
For the next five hours, the Hadassah conference room was a buzz of activity. Patients came and were examined. Most who were bald covered their heads with wigs or kerchiefs; their embarrassment was palpable. Zlotogorski pointed out the papules (tiny bumps) on the heads, elbows, and knees of the atrichia patients—subtle manifestations that help clinicians distinguish the disease from the autoimmune form of alopecia universalis. Questions and answers were translated into Hebrew, Arabic, and English. As lunchtime came and went, pastries disappeared from the middle of a long oval conference table.
Researchers took blood samples and skin biopsies and sketched out family pedigrees on scrap paper. Patients with alopecia universalis were given steroid shots in their eyebrows in hopes of revving up hair growth. As Zlotogorski injected a 14-year-old Israeli girl—who held her bald mother's hand and flinched at the needle—Christiano watched and winced with her. "It brings back so many memories," she said.
"But you're cured, right?" asked Basel Saad Edin, a Hadassah physician from the West Bank.
"You're never cured," Christiano said. "You wake up every morning and you feel . . ." The sentence trailed off as she patted the back of her head. "Too many memories," she finally said.
"In Arabic, there's a saying: If there's a crisis, sometimes it benefits other people," the Palestinian physician said. He reflected on the international effort fueled by Christiano's own disease—an effort that has brought scientists closer than ever before to finding the genetic basis of alopecia areata and its more extreme variants. "Maybe," he said, "it's a good thing you had this problem."