Unsolved cases: 5 diagnoses that still perplex physicians
Key Takeaways
In the last century, research has led to improved diagnoses, cures for serious maladies, and even eradication of some diseases. When patients fall ill, they can typically count on a doctor to pinpoint the cause and prescribe a treatment that leads to better health.
Despite these advances, medicine doesn’t always have the answer. Anomalies—from unexplainable neurological phenomena to genetic defects—have stumped medical experts for decades.
Here are five of these anomalies and the mysteries that surround them.
Syndrome X
A condition that has long gone unnamed because of a lack of known cases, syndrome X describes a rate of development that is dramatically delayed or even arrested. In one case, a 16-year-old girl was the size of an infant and had the mental capacity of a toddler, but she was never diagnosed with a genetic syndrome or chromosomal abnormality that could explain why. Experts have hypothesized that a glitch in her genes might have blocked healthy development, but they’ve struggled to find the precise “genetic culprit” responsible.
A study published in the journal Aging reported five cases of this developmental anomaly.
While these children experienced delayed maturation marked by toddler-like features, the rate of development in their blood tissues was normal, researchers found. This suggests that syndrome X is not caused by tissue-specific aging, but by other factors that remain hidden.
In 2017, researchers performed whole-genome sequence analysis in seven girls with syndrome X, which identified five de novo mutations (ie, mutations that appear in a person despite not appearing in their parents) in some, but not all, of the patients. The researchers proposed the name “neotenic complex syndrome” to better characterize the condition. Despite the new name, the syndrome remains nearly as mysterious as before.
Morgellons disease
Controversial among healthcare professionals, Morgellons disease is a skin condition characterized by fibers perceived to lie beneath, embed within, or protrude from the skin. Patients often complain of burning, stinging, and crawling sensations under their skin. Some report itching, pain, and difficulty falling asleep.
Some physicians and researchers have dismissed Morgellons disease, claiming that it’s a delusion tied to a mental health condition. Others believe the disease results from a physiological response to an infectious agent within the body. Specifically, the bacteria that causes Lyme disease—Borrelia burgdorferi—might trigger an overproduction of filaments, which in turn cause aggravating symptoms.
Still, researchers have yet to pin down conclusive evidence, and the real cause of the disorder remains unknown.
Highly superior autobiographical memory
Patients with highly superior autobiographical memory (HSAM) have the ability to recall dates, days, and details of personal experiences that occurred throughout their life with remarkable accuracy. Fewer than 100 people have been diagnosed with the condition, which some consider a burden because the ability can be uncontrollable and tiresome.
In an interview with Time, James McGaugh, PhD, a research professor in neurobiology and behavior at the University of California, Irvine, said he has identified a number of younger people, including one as young as age 8, with the ability. “This proves that it’s not just present in mature adults, and it’s not something that is learned and rehearsed over time.”
In a study published in the Proceedings of the National Academy of Sciences, Dr. McGaugh and colleagues found that individuals with HSAM showed more efficient memory access than others, along with enhanced brain activity in the prefrontal-hippocampal circuit.
The authors predicted that the study could inform future research on therapeutic interventions for memory disorders like Alzheimer’s disease.
Chimeric people
A chimera is an organism made up of cells with more than one distinct genotype. In other words: one person with two sets of DNA.
This condition can manifest in fraternal twins during early pregnancy, when one embryo dies and the other absorbs its twin’s cells. The remaining fetus will have two sets of DNA. A person can also become a chimera through a bone marrow transplant. Bone marrow contains stem cells that develop into red blood cells, which remain genetically identical to the donor.
What mystifies experts most seems like a simple question: How many chimeras exist? Many people might not even know they are a chimera.
This lack of awareness has been problematic for at least one woman, who almost lost custody of her children after genetic testing indicated they weren’t hers, despite having birthed them.
The good news is that chimerism is unlikely to cause harm or change how a person behaves.
Water allergy
Also known as aquagenic urticaria, this condition causes the skin to break out in hives within 20-30 minutes following skin contact with water of any temperature, purity, or salt content—even sweat and tears. The rash manifests as small, red or skin-colored welts that can appear anywhere on the body but are most common on the neck, upper trunk, and arms. It can also be itchy. Lesions typically resolve within 30-60 minutes of ending water contact with the skin. Oral ingestion of water by drinking is generally safe; however, saliva on the skin may cause a reaction.
Fewer than 100 known cases of aquagenic urticaria exist, making it especially difficult for experts to study.
Scientists have theorized that an allergen in water triggers an immune response in some people. Others argue the hives come from a toxic substance produced by the interaction between water and a substance on the skin.
Antihistamines are often used to manage the reaction, although anti-IgE antibodies have been used for patients who don’t respond to antihistamines. In more debilitating cases, people with aquagenic urticaria must limit their exposure to water.
What these mysteries say about medicine
While these mysteries continue to puzzle physicians, scientists, and the patients who live with them, each condition demonstrates the complexity of the human body and its functions. From a single cell that develops into a system of trillions, the mechanisms that power life are unique, complicated, and fragile. The beauty—and challenge—of medicine is in embracing this diversity and not relying on a one-size-fits-all solution.
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