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Cutting-edge lab work cracks a medical mystery
A deep dive into Kenneth Hobby's DNA yielded a correct diagnosis and relief from disabling pain.
Kenneth Hobby assumed his fever, fatigue, and aching pains in May 2018 were from another bout of malaria. He was on one of his frequent visits to Zambia in southern Africa, where the mosquito-borne parasite is common. But anti-malaria drugs didn't help, and soon Kenneth had such disabling pain that he could barely walk.
It wasn't malaria. After two years of seeing multiple specialists, Kenneth learned he had a rare but treatable blood condition known as clonal cytopenia of undetermined significance. Epigenetic testing at Mayo Clinic gave Kenneth the correct diagnosis.
"Without these new lab-based technologies, we would not have been able to diagnose Kenneth," says Mrinal Patnaik, M.B.B.S., a blood-disease specialist at Mayo Clinic in Rochester, Minnesota. "The work done by laboratory scientists is so instrumental to the quality of care that we provide. We physicians are highly grateful for that."
Clobbered by baffling symptoms
Kenneth spent much of his childhood in Zambia before becoming a clinical psychologist and professor in Searcy, Arkansas. He and his wife have four adult children and nine grandchildren.
In 1998, Kenneth started traveling regularly to Zambia to oversee a college scholarship program that he started. After getting sick and returning home in 2018, Kenneth just couldn't shake the symptoms.
"Every two weeks, it seems like I just got clobbered," he says. "My temperature would go up to 102 degrees. I had complete fatigue, a skin rash, and a lot of pain to where I could hardly walk. Nothing seemed to help."
Kenneth's doctor ruled out malaria and referred him to an infectious disease specialist, who was also baffled. Kenneth subsequently saw specialists in blood diseases, inflammatory diseases, and cancer. Blood tests found that he had slightly low blood-cell counts and markers of inflammatory disease. But no one knew why, or what treatment, if any, might help.
Kenneth's family and students were worried. "I was still making it to my classes at the university, but I wasn't worth much in the evening," he says. Due in part to his health, Kenneth retired in 2019.
Beyond conventional blood tests
Out of options, Kenneth's doctor recommended Mayo Clinic. In 2020, Kenneth met Dr. Patnaik, an expert in the diagnosis of cytopenia — the medical term for low blood-cell counts. Cytopenia often has an obvious cause, such as a side effect of certain medications. When the obvious causes are ruled out, as they were in Kenneth's case, finding an explanation is challenging.
"Patients with cytopenia are quite sick. But because they don't fit into a particular compartment in terms of diagnosis, they get referred from one specialist to another," Dr. Patnaik says. "I recall that Kenneth was fairly demoralized because of just how long he'd had these symptoms without getting an answer."
About 40% of unexplained cytopenia occurs when a portion of the blood cells carry an acquired genetic mutation. That rare condition is known as clonal cytopenia.
"A subset of clonal cytopenia cases are highly inflammatory. They release chemicals that mediate fever, chills, and rashes — all of which Kenneth had," Dr. Patnaik says.
Conventional blood tests can't diagnose clonal cytopenia. "I knew the next step had to be interrogating Kenneth's genome and epigenome," Dr. Patnaik says.
Restored quality of life
The rapidly emerging field of epigenetics goes beyond exploring an individual's genetic material to examine chemical changes that regulate DNA. Genetic testing of Kenneth's blood cells at Mayo Clinic Laboratories (Mayo ID: NGSHM) found two genetic mutations, known as IDH2 and SRSF2. IDH2 alters the epigenome by generating a cancer-causing substance called 2-HG. Additional testing found elevated levels of 2-HG and corresponding changes in DNA activity.
"With the help of these tests, we could establish a diagnosis of clonal cytopenia of undetermined significance," Dr. Patnaik says
He recommended monthly infusions of an epigenetic agent. Within four months, Kenneth's blood-cell counts and skin rashes improved, and his fevers ended.
"WE WERE ABLE TO GIVE HIM BACK HIS QUALITY OF LIFE AND THE DIGNITY HE DESERVES," DR. PATNAIK SAYS.
The monthly infusions cause side effects for about three days. "It's manageable," Kenneth says. "The rest of the month, I feel pretty normal." His daily exercise includes yoga and workouts on a stationary bike and exercise track.
Above all, Kenneth is grateful to feel well enough to enjoy time with his family. "I'm so appreciative for what Mayo does," he says. "I wouldn't be in as good of shape as I am if I hadn't gone to Mayo. I'm certain of that."