Catherine O’Hara, the acclaimed actress best known for her unforgettable portrayal of Moira Rose in Schitt’s Creek, along with iconic roles in Home Alone and Beetlejuice, passed away on January 30, 2026, at the age of 72. The exact cause of her death has not been disclosed. Throughout her life, she lived with a rare congenital disorder known as situs inversus, where the major internal organs are arranged in a mirrored position compared to the typical human anatomy. This condition came to light in media reports following her passing.
O’Hara discovered her unusual organ placement entirely by accident. The revelation occurred during routine testing for tuberculosis exposure, required because her son attended kindergarten. A simple chest X-ray showed that her heart was positioned on the right side instead of the left. She responded with her characteristic humor, calling herself a weirdo and noting her mixed feelings about medical interventions.
In an interview, O’Hara shared her lighthearted take on the discovery. “I’m a weirdo! I appreciate Western medicine, I just don’t want to be part of it.” She deliberately avoided diving deeper into the details of her condition. O’Hara even admitted to not memorizing the medical term, preferring to remain blissfully unaware since it had never impacted her daily life before the diagnosis.
She described the name vaguely in her own words. “I don’t even know its name because I don’t want to know it. Something cardio-inversa, then dextro-cardia and something-inversa… People will think I’m ignorant, but somehow I don’t want to know, because I didn’t know before either.” O’Hara suspected she had the form involving dextrocardia, where the heart points toward the right side of the chest. Her relaxed attitude highlighted how the condition caused her no significant trouble.
Situs inversus involves a complete or partial reversal of the internal organs’ positions. During embryonic development, the usual left-right organization flips, placing organs in a mirror-image layout. For instance, the left atrium of the heart and the left lung lobe end up on the right side of the body. The liver often shifts to the left, while the stomach and spleen appear on the right.
Medical experts estimate that situs inversus occurs in approximately one out of every 10,000 individuals. It appears slightly more frequently in men than women. Data from the Cleveland Clinic explains that in affected people, “the left atrium of the heart and the left lung lobe are located on the right side of the body, the liver may be positioned on the left, while the stomach and spleen are often on the right side.” Many individuals go their entire lives without realizing they have this arrangement.
Two primary variations exist within the condition. The first, dextrocardia with situs inversus, features the heart directed toward the right along with fully mirrored organs, matching what O’Hara believed she experienced. The second type, levocardia with situs inversus, keeps the heart’s apex on the left but reverses the positions of other organs. Both forms stem from the same developmental reversal.
Genetic factors drive the development of situs inversus. A person must inherit mutated genes from both parents for the condition to manifest. Researchers have identified more than 100 genes connected to disruptions in organ positioning. Additional risks include a family history of birth defects, gestational diabetes, maternal smoking, certain medications taken during pregnancy, and lower socioeconomic circumstances.
Most people with isolated situs inversus experience no health problems whatsoever. Their organs function perfectly despite the unusual locations. Numerous cases remain undiscovered because no symptoms arise. However, challenges can emerge when the reversal accompanies other disorders, such as congenital heart defects or primary ciliary dyskinesia, which leads to mucus accumulation in the lungs and recurrent bronchitis or sinusitis.
Awareness of the condition proves crucial for medical care. Doctors might initially misinterpret symptoms or imaging results based on standard anatomy, potentially delaying accurate diagnosis or treatment. Surgical procedures also require extra caution to account for the mirrored layout. Fortunately, situs inversus itself rarely shortens life expectancy.
No specific treatment exists for situs inversus alone, as it typically causes no impairment. Medical professionals do not recommend surgery to reposition organs, and no therapies can reverse the arrangement. Patients simply manage any related complications if they develop. With proper awareness, individuals lead full, normal lives.
Situs inversus represents a fascinating example of human anatomical variation that develops early in the womb. The process of left-right asymmetry normally establishes itself through complex cellular signaling, but genetic mutations can flip the pattern entirely. When the reversal is complete and isolated, it rarely affects overall health or fertility. Imaging tests like X-rays, ultrasounds, or CT scans most commonly detect it incidentally during unrelated medical evaluations.
Primary ciliary dyskinesia, mentioned as a possible associated disorder, impairs the tiny hair-like structures that clear mucus from airways. About half of people with this ciliary problem also exhibit situs inversus due to shared developmental mechanisms. This combination sometimes receives the name Kartagener syndrome, characterized by chronic respiratory infections alongside the organ reversal. Early recognition helps manage symptoms effectively through routine care and preventive measures.
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