Finding patients
Many of these rare diseases that plague young patients are unmistakable. Children with moderate or severe dystrophic epidermolysis bullosa, for instance, carry a mutation that prevents them from making type VII collagen. The babies suffer wounds and excessive bleeding and tend to receive a quick diagnosis within the first 6 months of life, according to Andy Orth, chief commercial officer at Krystal Bio, manufacturer of a new wound-healing gene therapy, Vyjuvek, for the disorder.
Other rare neurologic or muscular diseases can go undiagnosed for years. Until recently, drug companies and researchers have had little motivation to speed up the timeline because early diagnosis of a disease like DMD would not change the outcome, Dr. Nelson said.
But with gene therapy, prognoses are changing. And finding diseases early could soon mean preserving muscular function or preventing neurologic damage, Dr. Duncan said.
Newborn sequencing “is not standard of care yet, but it’s certainly coming,” Josh Peterson, MD, MPH, director of the center for precision medicine at Vanderbilt University Medical Center, in Nashville, Tenn., told this news organization.
A recent survey of 238 specialists in rare diseases found that roughly 90% believe whole-genome sequencing should be available to all newborns. And 80% of those experts endorse 42 genes as disease predictors. Screening for rare diseases at birth could reveal a host of conditions in the first week of life and expedite treatment. But this strategy will often rely on primary care and pediatricians interpreting the results.
Most pediatricians think sequencing is a great idea, but they do not feel comfortable doing it themselves, Dr. Peterson said. The good news, he said, is that manufacturers have made screening tests straightforward. Some drug companies even offer free screenings for gene therapy candidates.
Dr. Peterson predicts pediatricians will need to be equipped to deliver negative results on their own, which will be the case for around 97%-99% of patients. They also will need to be clear on whether a negative result is definitive or if more testing is warranted.
Positive results are more nuanced. Genetic counseling is the ideal resource when delivering this kind of news to patients, but counselors are a scarce resource nationally – and particularly in rural areas, Dr. Nelson said. Physicians likely will have to rely on their own counseling training to some degree.
“I feel very strongly that genetic counselors are in short supply,” Ms. Gibbons in Colorado said. Patients need a friendly resource who can talk them through the disease and how it works. And that discussion is not a one-off, she said.
The number of board-certified genetic counselors in the United States has doubled to more than 6,000 in the past 10 years – a pace that is expected to continue, according to the National Society of Genetic Counselors. “However, the geographical distribution of genetic counselors is most concentrated in urban centers.”
Equally important to the counseling experience, according to Dr. Duncan at Boston Children’s, is a primary care physician’s network of connections. The best newborn screening rollouts across the country have succeeded because clinicians knew where to send people next and how to get families the help they needed, she said.
But she also cautioned that this learning curve will soon be overwhelming. As gene therapy expands, it may be difficult for primary care doctors to keep up with the science, treatment studies, and commercially available therapies. “It’s asking too much,” Dr. Duncan said.
The structure of primary care already stretches practitioners thin and will “affect how well precision medicine can be adopted and disseminated,” Dr. Peterson said. “I think that is a key issue.”
Artificial intelligence may offer a partial solution. Some genetic counseling models already exist, but their utility for clinicians so far is limited, Dr. Beales said. But he said he expects these tools to improve rapidly to help clinicians and patients. On the patient’s end, they may be able to answer questions and supplement basic genetic counseling. On the physician’s end, algorithms could help triage patients and help move them along to the next steps in the care pathway for these rare diseases.