Why this case matters
Bardet-Biedl syndrome (BBS) is a rare inherited condition that can affect many parts of the body. Its well-recognized features include retinal dystrophy, obesity, extra fingers or toes, kidney dysfunction, and hypogonadism. High blood pressure is also frequently seen in people with BBS, although it is not currently part of the condition’s diagnostic criteria and has received comparatively limited study.
That can make hypertension in BBS easy to attribute to the syndrome’s broader effects on kidney health, metabolism, and body weight. A newly reported case, however, shows why clinicians should also look carefully for secondary causes of hypertension—specific, potentially treatable medical conditions that drive blood pressure upward. In this case, a 35-year-old man with clinically diagnosed BBS had primary hyperaldosteronism caused by a benign adrenal gland tumor.
The report is believed to be the first description of an aldosterone-producing adrenal adenoma in a person with BBS. Its central message is practical: severe or difficult-to-control hypertension in BBS should not automatically be considered an unavoidable feature of the syndrome.
A clue beyond ordinary hypertension: low potassium
The patient developed severe hypertension that remained resistant to treatment. He also had hypokalaemia, meaning low potassium levels in the blood. This combination can be an important signal of excess aldosterone.
Aldosterone is a hormone made by the adrenal glands, two small glands that sit above the kidneys. It helps regulate salt, fluid balance, potassium, and blood pressure. When the body produces too much aldosterone, the kidneys retain more sodium and water, which can raise blood pressure. At the same time, potassium can be lost in the urine, leading to hypokalaemia.
The researchers performed a detailed endocrine evaluation. Testing showed an elevated aldosterone-to-renin ratio. Renin is part of a hormonal system that helps regulate blood pressure; in primary hyperaldosteronism, aldosterone is inappropriately high while renin is typically suppressed. Saline suppression testing then supported the diagnosis. This test examines whether aldosterone production falls appropriately after salt-containing fluid is given.
Imaging identified a unilateral adrenal adenoma—an abnormal growth in one adrenal gland—as the likely source of the excess aldosterone. The patient underwent laparoscopic adrenalectomy, surgery to remove the affected adrenal gland. Following surgery, his potassium level normalized and his blood pressure control improved substantially.
Understanding “secondary” hypertension
Hypertension can arise for many reasons. In BBS, high blood pressure may be influenced by kidney dysfunction, metabolic changes, obesity, and possibly neuroendocrine mechanisms. These factors can overlap and make it challenging to identify the precise reason a person’s blood pressure is elevated.
Primary hyperaldosteronism is different because it is a defined endocrine cause of hypertension. The word “primary” refers to aldosterone being produced directly by the adrenal glands rather than being stimulated by another condition. In this report, the adenoma was producing aldosterone in excess.
Recognizing this distinction matters because the treatment pathway can change. Rather than only escalating blood-pressure medicines, clinicians may investigate hormonal causes and, where a one-sided adrenal lesion is responsible, consider surgery. In this patient, removing the adenoma addressed the source of hormone excess and improved both potassium balance and blood pressure management.
What the report does—and does not—show about BBS
The case raises an intriguing scientific question: could BBS biology somehow contribute to aldosterone-related hypertension? BBS is a ciliopathy, meaning it involves dysfunction of microscopic cell structures called cilia. The proteins affected in BBS are often described collectively as the BBSome. Existing evidence suggests BBSome dysfunction may affect metabolic and cardiovascular regulation.
However, this single case cannot establish that BBS causes aldosterone-producing adenomas. The authors emphasize that the coexistence of BBS and primary aldosteronism could be coincidental. At the same time, shared molecular pathways cannot yet be ruled out. This uncertainty is important: the case is a reason for further research, not proof of a direct biological link.
Implications for care and future research
For patients and families, the report reinforces the value of individualized assessment. High blood pressure in BBS may have multiple contributors, and features such as severe hypertension, poor response to treatment, or low potassium may prompt a more comprehensive endocrine work-up. Identifying a specific cause can open the door to more targeted treatment.
For researchers, the case highlights a gap in knowledge about cardiovascular and hormonal regulation in BBS. Future studies could examine how often primary hyperaldosteronism occurs in BBS, whether adrenal hormone abnormalities are more common in particular genetic forms of the condition, and how kidney, metabolic, and cilia-related pathways interact in hypertension.
As care for inherited retinal diseases increasingly considers the whole person—not only vision—reports like this one are valuable. They show that investigating symptoms beyond the eye can reveal treatable conditions and may eventually deepen understanding of the complex, body-wide effects of Bardet-Biedl syndrome.