Guest post, by Ricki Lewis
Ricki Lewis is a geneticist and science writer. St. Martin’s Press just published “The Forever Fix: Gene Therapy and the Boy Who Saved It.” Ricki’s textbook Human Genetics: Concepts and Applications, from McGraw-Hill Higher Education, is in its 10th edition.
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A challenge of living with a genetic disease, especially a very rare one, is that the mutation may affect different body parts. A health care practitioner may not consider a patient’s inherited condition, especially if the most recognizable symptoms don’t fall into his or her specialty.
Shirley Banks discovered the importance of seeking a second, specialized opinion when the doctor she’d been seeing for many years had a disturbing reaction to a question.
The Long Road to a Diagnosis
The Banks family has osteogenesis imperfecta (OI) which affects 1 in 20,000 live births. Shirley, now 73, can trace the “brittle bone disease” back to her grandmother and a great uncle, who were two of seven children. They had type I OI, which is autosomal dominant, affecting each generation and both sexes.
Shirley remembers the disease appearing in first one brother, then another, when she was a child in upstate New York. “When my first brother was growing up he had many fractures, and the doctors told him to eat high calcium foods. We lived on a farm! All the dairy made no difference because of the mutation, but nobody knew.” Several cousins easily broke bones too, and Shirley had it but didn’t realize it. Years later, her son Todd inherited the family legacy.
“Todd was a very active kid. He had his first fracture at 2, when he tripped and broke his leg. I became suspicious because my brother’s child broke bones too. Finally, a doctor who had come across this disease as an intern explained it, and we were diagnosed. It wasn’t until the early 1960s that we recognized we had a disease,” Shirley says.
More Than Brittle Bones
Shirley’s OI is, thankfully, mild. “The only bones I’ve broken are in my toes from when I ran into furniture,” she explains. Like many with OI she has other symptoms. She wears digital hearing aids and the whites of her eyes (sclerae) have a bluish cast, a hallmark of the disease. The disease can also cause discolored brittle teeth, muscle weakness, fatigue, and loose joints.
Even a mild case of OI can lead to problems, which Shirley learned when she had a hysterectomy in 1983. She’d taken aspirin beforehand, and informed the medical staff of her OI, but “when they got in there everywhere they touched, I bled. And when the doctor went to sew me up, the tissue kept ripping.” She nearly died. OI makes many tissues fragile – but the medical staff had been unaware of this.
The Banks family has a mutation in a major gene for the connective tissue protein collagen. Their type I is usually manageable, with 1-100 fractures in a lifetime; other forms begin to break bones before birth, proving lethal in infancy. Before genetic testing for OI became possible, some parents of children with broken bones were falsely accused of
child abuse. The other types began to be described when parents accused of child abuse “failed” the genetic test for type I. Eight forms of OI are now recognized.
Only a few cases of OI are known from history. An Egyptian mummy from 1000 B.C. had it, as did 9th century Viking “Ivan the Boneless,” who was reportedly comported into battle aboard a shield and whose remains were exhumed and burnt by King William I, forever obscuring the true diagnosis.
An OI Eye is Not a Normal Eye
People with OI are at higher risk for developing glaucoma, which results from high pressure in the eyeball. The corneas of people with OI are abnormally thin, which makes the pressure read as lower than it actually is, which can delay preventive treatment if a physician is unfamiliar with this and other effects of OI on the eye. That’s what happened to Shirley, who was diagnosed with glaucoma at 38.
Patients with osteogenesis imperfecta may have high intraocular pressure and glaucoma.
A few months ago, the ophthalmologist who’d been prescribing Shirley’s glaucoma drugs for many years told her she needed cataract surgery. “So I asked him if my OI would complicate anything. He looked at me and said no, it’s the same procedure.”
Had the doctor also been treating her glaucoma without considering her OI? Shirley grew concerned.
Todd had just had surgery to drain the fluid (aqueous humor) that was building up the pressure in his eyes. Would his doctor provide a second opinion, on Shirley’s glaucoma and cataracts? She sought a second, more experienced opinion from another ophthalmologist.
“I learned so much more in his exam, I took tests I’d never had with the other eye doctor, who wasn’t looking at the special condition of osteogenesis imperfecta,” Shirley says. The good news: the cataract surgery could wait. The disturbing news: She hadn’t been getting high enough doses of the glaucoma medicine, and the pressure in her eyes had already damaged her optic nerves.
“The other physician wasn’t looking at your special condition. You and your son are a whole different ballgame,” said the second doctor. OI can directly harm the optic nerve and the tissues that support it, plus the spongy tissue that normally drains fluid from the eye. “I might have ended up blind in 3 years,” Shirley says.
Lesson learned, according to Shirley Banks: “It pays to go to a specialist. People procrastinate, say ‘oh you don’t need a specialist for something as common as glaucoma.’ But it’s different if there’s a genetic disease.”
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